diff --git a/toolchain/check/testdata/alias/fail_bool_value.carbon b/toolchain/check/testdata/alias/fail_bool_value.carbon
index 3828cd96aceb..678258538acc 100644
--- a/toolchain/check/testdata/alias/fail_bool_value.carbon
+++ b/toolchain/check/testdata/alias/fail_bool_value.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/alias/fail_bool_value.carbon
 
-// CHECK:STDERR: fail_bool_value.carbon:[[@LINE+3]]:11: error: alias initializer must be a name reference [AliasRequiresNameRef]
+// CHECK:STDERR: fail_bool_value.carbon:[[@LINE+4]]:11: error: alias initializer must be a name reference [AliasRequiresNameRef]
 // CHECK:STDERR: alias a = false;
 // CHECK:STDERR:           ^~~~~
+// CHECK:STDERR:
 alias a = false;
 let a_test: bool = a;
 
diff --git a/toolchain/check/testdata/alias/fail_builtins.carbon b/toolchain/check/testdata/alias/fail_builtins.carbon
index 8efaccf848c4..0d60e0484c95 100644
--- a/toolchain/check/testdata/alias/fail_builtins.carbon
+++ b/toolchain/check/testdata/alias/fail_builtins.carbon
@@ -14,9 +14,10 @@
 // CHECK:STDERR:
 alias a = i32;
 
-// CHECK:STDERR: fail_builtins.carbon:[[@LINE+3]]:11: error: alias initializer must be a name reference [AliasRequiresNameRef]
+// CHECK:STDERR: fail_builtins.carbon:[[@LINE+4]]:11: error: alias initializer must be a name reference [AliasRequiresNameRef]
 // CHECK:STDERR: alias b = bool;
 // CHECK:STDERR:           ^~~~
+// CHECK:STDERR:
 alias b = bool;
 
 // CHECK:STDOUT: --- fail_builtins.carbon
diff --git a/toolchain/check/testdata/alias/fail_control_flow.carbon b/toolchain/check/testdata/alias/fail_control_flow.carbon
index 3438a16abe4f..f6a94949745b 100644
--- a/toolchain/check/testdata/alias/fail_control_flow.carbon
+++ b/toolchain/check/testdata/alias/fail_control_flow.carbon
@@ -8,21 +8,22 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/alias/fail_control_flow.carbon
 
-// CHECK:STDERR: fail_control_flow.carbon:[[@LINE+15]]:11: error: semantics TODO: `Control flow expressions are currently only supported inside functions.` [SemanticsTodo]
+// CHECK:STDERR: fail_control_flow.carbon:[[@LINE+16]]:11: error: semantics TODO: `Control flow expressions are currently only supported inside functions.` [SemanticsTodo]
 // CHECK:STDERR: alias a = true or false;
 // CHECK:STDERR:           ^~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_control_flow.carbon:[[@LINE+11]]:11: error: semantics TODO: `Control flow expressions are currently only supported inside functions.` [SemanticsTodo]
+// CHECK:STDERR: fail_control_flow.carbon:[[@LINE+12]]:11: error: semantics TODO: `Control flow expressions are currently only supported inside functions.` [SemanticsTodo]
 // CHECK:STDERR: alias a = true or false;
 // CHECK:STDERR:           ^~~~~~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_control_flow.carbon:[[@LINE+7]]:11: error: semantics TODO: `Control flow expressions are currently only supported inside functions.` [SemanticsTodo]
+// CHECK:STDERR: fail_control_flow.carbon:[[@LINE+8]]:11: error: semantics TODO: `Control flow expressions are currently only supported inside functions.` [SemanticsTodo]
 // CHECK:STDERR: alias a = true or false;
 // CHECK:STDERR:           ^~~~~~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_control_flow.carbon:[[@LINE+3]]:11: error: alias initializer must be a name reference [AliasRequiresNameRef]
+// CHECK:STDERR: fail_control_flow.carbon:[[@LINE+4]]:11: error: alias initializer must be a name reference [AliasRequiresNameRef]
 // CHECK:STDERR: alias a = true or false;
 // CHECK:STDERR:           ^~~~~~~~~~~~~
+// CHECK:STDERR:
 alias a = true or false;
 
 // CHECK:STDOUT: --- fail_control_flow.carbon
@@ -35,7 +36,7 @@ alias a = true or false;
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
-// CHECK:STDOUT:   %.loc26: bool = block_arg <unexpected instblockref inst_block5> [template = constants.%true]
+// CHECK:STDOUT:   %.loc27: bool = block_arg <unexpected instblockref inst_block5> [template = constants.%true]
 // CHECK:STDOUT:   %a: <error> = bind_alias a, <error> [template = <error>]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/alias/no_prelude/export_name.carbon b/toolchain/check/testdata/alias/no_prelude/export_name.carbon
index 775b0833ff14..83f4dab69204 100644
--- a/toolchain/check/testdata/alias/no_prelude/export_name.carbon
+++ b/toolchain/check/testdata/alias/no_prelude/export_name.carbon
@@ -53,9 +53,10 @@ library "[[@TEST_NAME]]";
 
 import library "export";
 
-// CHECK:STDERR: fail_orig_name_not_in_export.carbon:[[@LINE+3]]:8: error: name `C` not found [NameNotFound]
+// CHECK:STDERR: fail_orig_name_not_in_export.carbon:[[@LINE+4]]:8: error: name `C` not found [NameNotFound]
 // CHECK:STDERR: var c: C = {};
 // CHECK:STDERR:        ^
+// CHECK:STDERR:
 var c: C = {};
 
 // --- indirect_compat.carbon
@@ -204,7 +205,7 @@ var d: D* = &c;
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %.loc9: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %.loc10: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:   assign file.%c.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/alias/no_prelude/fail_aliased_name_in_diag.carbon b/toolchain/check/testdata/alias/no_prelude/fail_aliased_name_in_diag.carbon
index 1f4b82dab94d..25e61149adc8 100644
--- a/toolchain/check/testdata/alias/no_prelude/fail_aliased_name_in_diag.carbon
+++ b/toolchain/check/testdata/alias/no_prelude/fail_aliased_name_in_diag.carbon
@@ -14,9 +14,10 @@ class D {}
 alias c = C;
 var d: D = {};
 
-// CHECK:STDERR: fail_aliased_name_in_diag.carbon:[[@LINE+3]]:1: error: `Core.ImplicitAs` implicitly referenced here, but package `Core` not found [CoreNotFound]
+// CHECK:STDERR: fail_aliased_name_in_diag.carbon:[[@LINE+4]]:1: error: `Core.ImplicitAs` implicitly referenced here, but package `Core` not found [CoreNotFound]
 // CHECK:STDERR: let c_var: c = d;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 let c_var: c = d;
 
 // CHECK:STDOUT: --- fail_aliased_name_in_diag.carbon
@@ -62,7 +63,7 @@ let c_var: c = d;
 // CHECK:STDOUT:   %.loc15_14: init %D = converted %.loc15_13.1, %.loc15_13.2 [template = constants.%D.val]
 // CHECK:STDOUT:   assign file.%d.var, %.loc15_14
 // CHECK:STDOUT:   %d.ref: ref %D = name_ref d, file.%d
-// CHECK:STDOUT:   %.loc20: %C = converted %d.ref, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc21: %C = converted %d.ref, <error> [template = <error>]
 // CHECK:STDOUT:   %c_var: %C = bind_name c_var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/alias/no_prelude/fail_local_in_namespace.carbon b/toolchain/check/testdata/alias/no_prelude/fail_local_in_namespace.carbon
index e3efd77671b3..d41370b1953a 100644
--- a/toolchain/check/testdata/alias/no_prelude/fail_local_in_namespace.carbon
+++ b/toolchain/check/testdata/alias/no_prelude/fail_local_in_namespace.carbon
@@ -20,9 +20,10 @@ fn F() -> {} {
   // CHECK:STDERR:                ^~
   // CHECK:STDERR:
   alias NS.a = {};
-  // CHECK:STDERR: fail_local_in_namespace.carbon:[[@LINE+3]]:10: error: member name `a` not found in `NS` [MemberNameNotFoundInScope]
+  // CHECK:STDERR: fail_local_in_namespace.carbon:[[@LINE+4]]:10: error: member name `a` not found in `NS` [MemberNameNotFoundInScope]
   // CHECK:STDERR:   return NS.a;
   // CHECK:STDERR:          ^~~~
+  // CHECK:STDERR:
   return NS.a;
 }
 
diff --git a/toolchain/check/testdata/alias/no_prelude/fail_modifiers.carbon b/toolchain/check/testdata/alias/no_prelude/fail_modifiers.carbon
index 55320ddb20a0..2b1b7d5eb95b 100644
--- a/toolchain/check/testdata/alias/no_prelude/fail_modifiers.carbon
+++ b/toolchain/check/testdata/alias/no_prelude/fail_modifiers.carbon
@@ -43,9 +43,10 @@ abstract base default final alias A = Class;
 // CHECK:STDERR:
 impl alias B = Class;
 
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+3]]:1: error: `extern` not allowed on `alias` declaration [ModifierNotAllowedOnDeclaration]
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+4]]:1: error: `extern` not allowed on `alias` declaration [ModifierNotAllowedOnDeclaration]
 // CHECK:STDERR: extern alias C = Class;
 // CHECK:STDERR: ^~~~~~
+// CHECK:STDERR:
 extern alias C = Class;
 
 // CHECK:STDOUT: --- fail_modifiers.carbon
@@ -68,7 +69,7 @@ extern alias C = Class;
 // CHECK:STDOUT:   %A: type = bind_alias A, %Class.decl [template = constants.%Class]
 // CHECK:STDOUT:   %Class.ref.loc44: type = name_ref Class, %Class.decl [template = constants.%Class]
 // CHECK:STDOUT:   %B: type = bind_alias B, %Class.decl [template = constants.%Class]
-// CHECK:STDOUT:   %Class.ref.loc49: type = name_ref Class, %Class.decl [template = constants.%Class]
+// CHECK:STDOUT:   %Class.ref.loc50: type = name_ref Class, %Class.decl [template = constants.%Class]
 // CHECK:STDOUT:   %C: type = bind_alias C, %Class.decl [template = constants.%Class]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/alias/no_prelude/fail_name_conflict.carbon b/toolchain/check/testdata/alias/no_prelude/fail_name_conflict.carbon
index f4dc01c4f344..d57c2908bb23 100644
--- a/toolchain/check/testdata/alias/no_prelude/fail_name_conflict.carbon
+++ b/toolchain/check/testdata/alias/no_prelude/fail_name_conflict.carbon
@@ -21,12 +21,13 @@ alias a = C;
 var a: C = {};
 
 var b: C = {};
-// CHECK:STDERR: fail_name_conflict.carbon:[[@LINE+6]]:7: error: duplicate name being declared in the same scope [NameDeclDuplicate]
+// CHECK:STDERR: fail_name_conflict.carbon:[[@LINE+7]]:7: error: duplicate name being declared in the same scope [NameDeclDuplicate]
 // CHECK:STDERR: alias b = C;
 // CHECK:STDERR:       ^
 // CHECK:STDERR: fail_name_conflict.carbon:[[@LINE-4]]:5: note: name is previously declared here [NameDeclPrevious]
 // CHECK:STDERR: var b: C = {};
 // CHECK:STDERR:     ^
+// CHECK:STDERR:
 alias b = C;
 
 // CHECK:STDOUT: --- fail_name_conflict.carbon
@@ -51,8 +52,8 @@ alias b = C;
 // CHECK:STDOUT:   %a.loc21: ref %C = bind_name a, %a.var
 // CHECK:STDOUT:   %b.var: ref %C = var b
 // CHECK:STDOUT:   %b: ref %C = bind_name b, %b.var
-// CHECK:STDOUT:   %C.ref.loc30: type = name_ref C, %C.decl [template = constants.%C]
-// CHECK:STDOUT:   %.loc30: type = bind_alias <invalid>, %C.decl [template = constants.%C]
+// CHECK:STDOUT:   %C.ref.loc31: type = name_ref C, %C.decl [template = constants.%C]
+// CHECK:STDOUT:   %.loc31: type = bind_alias <invalid>, %C.decl [template = constants.%C]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: class @C {
diff --git a/toolchain/check/testdata/alias/no_prelude/fail_not_constant.carbon b/toolchain/check/testdata/alias/no_prelude/fail_not_constant.carbon
index 4dc22d5c4e26..5e19c89fca92 100644
--- a/toolchain/check/testdata/alias/no_prelude/fail_not_constant.carbon
+++ b/toolchain/check/testdata/alias/no_prelude/fail_not_constant.carbon
@@ -11,9 +11,10 @@
 fn F() {
   var a: () = ();
   var b: ()* = &a;
-  // CHECK:STDERR: fail_not_constant.carbon:[[@LINE+3]]:13: error: alias initializer must be a name reference [AliasRequiresNameRef]
+  // CHECK:STDERR: fail_not_constant.carbon:[[@LINE+4]]:13: error: alias initializer must be a name reference [AliasRequiresNameRef]
   // CHECK:STDERR:   alias c = *b;
   // CHECK:STDERR:             ^~
+  // CHECK:STDERR:
   alias c = *b;
 }
 
@@ -48,8 +49,8 @@ fn F() {
 // CHECK:STDOUT:   %addr: %ptr = addr_of %a.ref
 // CHECK:STDOUT:   assign %b.var, %addr
 // CHECK:STDOUT:   %b.ref: ref %ptr = name_ref b, %b
-// CHECK:STDOUT:   %.loc17_14: %ptr = bind_value %b.ref
-// CHECK:STDOUT:   %.loc17_13: ref %empty_tuple.type = deref %.loc17_14
+// CHECK:STDOUT:   %.loc18_14: %ptr = bind_value %b.ref
+// CHECK:STDOUT:   %.loc18_13: ref %empty_tuple.type = deref %.loc18_14
 // CHECK:STDOUT:   %c: <error> = bind_alias c, <error> [template = <error>]
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/alias/no_prelude/fail_params.carbon b/toolchain/check/testdata/alias/no_prelude/fail_params.carbon
index 3644ec33c5b6..479631b2624a 100644
--- a/toolchain/check/testdata/alias/no_prelude/fail_params.carbon
+++ b/toolchain/check/testdata/alias/no_prelude/fail_params.carbon
@@ -8,13 +8,14 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/alias/no_prelude/fail_params.carbon
 
-// CHECK:STDERR: fail_params.carbon:[[@LINE+7]]:8: error: `alias` declaration cannot have parameters [UnexpectedDeclNameParams]
+// CHECK:STDERR: fail_params.carbon:[[@LINE+8]]:8: error: `alias` declaration cannot have parameters [UnexpectedDeclNameParams]
 // CHECK:STDERR: alias A(T:! type) = T*;
 // CHECK:STDERR:        ^~~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_params.carbon:[[@LINE+3]]:21: error: alias initializer must be a name reference [AliasRequiresNameRef]
+// CHECK:STDERR: fail_params.carbon:[[@LINE+4]]:21: error: alias initializer must be a name reference [AliasRequiresNameRef]
 // CHECK:STDERR: alias A(T:! type) = T*;
 // CHECK:STDERR:                     ^~
+// CHECK:STDERR:
 alias A(T:! type) = T*;
 
 // CHECK:STDOUT: --- fail_params.carbon
diff --git a/toolchain/check/testdata/alias/no_prelude/import.carbon b/toolchain/check/testdata/alias/no_prelude/import.carbon
index de20cee0687f..cf6f4ffe9a1f 100644
--- a/toolchain/check/testdata/alias/no_prelude/import.carbon
+++ b/toolchain/check/testdata/alias/no_prelude/import.carbon
@@ -58,10 +58,11 @@ var b: () = a_alias;
 
 library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_var3.carbon:[[@LINE+4]]:1: in import [InImport]
+// CHECK:STDERR: fail_var3.carbon:[[@LINE+5]]:1: in import [InImport]
 // CHECK:STDERR: var2.carbon:8:5: error: semantics TODO: `Non-constant ImportRefLoaded (comes up with var)` [SemanticsTodo]
 // CHECK:STDERR: var b: () = a_alias;
 // CHECK:STDERR:     ^
+// CHECK:STDERR:
 import library "var2";
 
 var c: () = a_alias_alias;
@@ -246,9 +247,9 @@ var c: () = a_alias_alias;
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %a_alias_alias.ref: ref %empty_tuple.type = name_ref a_alias_alias, imports.%import_ref.692 [template = <error>]
-// CHECK:STDOUT:   %.loc10_13: init %empty_tuple.type = tuple_init () to file.%c.var [template = constants.%empty_tuple]
-// CHECK:STDOUT:   %.loc10_26: init %empty_tuple.type = converted %a_alias_alias.ref, %.loc10_13 [template = constants.%empty_tuple]
-// CHECK:STDOUT:   assign file.%c.var, %.loc10_26
+// CHECK:STDOUT:   %.loc11_13: init %empty_tuple.type = tuple_init () to file.%c.var [template = constants.%empty_tuple]
+// CHECK:STDOUT:   %.loc11_26: init %empty_tuple.type = converted %a_alias_alias.ref, %.loc11_13 [template = constants.%empty_tuple]
+// CHECK:STDOUT:   assign file.%c.var, %.loc11_26
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/alias/no_prelude/import_access.carbon b/toolchain/check/testdata/alias/no_prelude/import_access.carbon
index 8c45de77242e..8016a1d92acf 100644
--- a/toolchain/check/testdata/alias/no_prelude/import_access.carbon
+++ b/toolchain/check/testdata/alias/no_prelude/import_access.carbon
@@ -47,9 +47,10 @@ package Other library "[[@TEST_NAME]]";
 
 import Test library "def";
 
-// CHECK:STDERR: fail_other_def.carbon:[[@LINE+3]]:11: error: member name `A` not found in `Test` [MemberNameNotFoundInScope]
+// CHECK:STDERR: fail_other_def.carbon:[[@LINE+4]]:11: error: member name `A` not found in `Test` [MemberNameNotFoundInScope]
 // CHECK:STDERR: var inst: Test.A = {};
 // CHECK:STDERR:           ^~~~~~
+// CHECK:STDERR:
 var inst: Test.A = {};
 
 // CHECK:STDOUT: --- def.carbon
@@ -166,7 +167,7 @@ var inst: Test.A = {};
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %.loc9: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %.loc10: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:   assign file.%inst.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/array/fail_bound_negative.carbon b/toolchain/check/testdata/array/fail_bound_negative.carbon
index b77455c9a163..bda5d622557b 100644
--- a/toolchain/check/testdata/array/fail_bound_negative.carbon
+++ b/toolchain/check/testdata/array/fail_bound_negative.carbon
@@ -10,9 +10,10 @@
 
 fn Negate(n: i32) -> i32 = "int.snegate";
 
-// CHECK:STDERR: fail_bound_negative.carbon:[[@LINE+3]]:14: error: array bound of -1 is negative [ArrayBoundNegative]
+// CHECK:STDERR: fail_bound_negative.carbon:[[@LINE+4]]:14: error: array bound of -1 is negative [ArrayBoundNegative]
 // CHECK:STDERR: var a: [i32; Negate(1)];
 // CHECK:STDERR:              ^~~~~~~~~
+// CHECK:STDERR:
 var a: [i32; Negate(1)];
 
 // CHECK:STDOUT: --- fail_bound_negative.carbon
diff --git a/toolchain/check/testdata/array/fail_bound_overflow.carbon b/toolchain/check/testdata/array/fail_bound_overflow.carbon
index b9fa33b71e16..3e9f005761b9 100644
--- a/toolchain/check/testdata/array/fail_bound_overflow.carbon
+++ b/toolchain/check/testdata/array/fail_bound_overflow.carbon
@@ -14,12 +14,13 @@
 // CHECK:STDERR:
 var a: [i32; 39999999999999999993];
 
-// CHECK:STDERR: fail_bound_overflow.carbon:[[@LINE+6]]:9: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_bound_overflow.carbon:[[@LINE+7]]:9: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var b: [1; 39999999999999999993];
 // CHECK:STDERR:         ^
-// CHECK:STDERR: fail_bound_overflow.carbon:[[@LINE+3]]:9: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
+// CHECK:STDERR: fail_bound_overflow.carbon:[[@LINE+4]]:9: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
 // CHECK:STDERR: var b: [1; 39999999999999999993];
 // CHECK:STDERR:         ^
+// CHECK:STDERR:
 var b: [1; 39999999999999999993];
 
 // CHECK:STDOUT: --- fail_bound_overflow.carbon
diff --git a/toolchain/check/testdata/array/fail_incomplete_element.carbon b/toolchain/check/testdata/array/fail_incomplete_element.carbon
index 646553e5fc29..27f8af3a94d7 100644
--- a/toolchain/check/testdata/array/fail_incomplete_element.carbon
+++ b/toolchain/check/testdata/array/fail_incomplete_element.carbon
@@ -10,12 +10,13 @@
 
 class Incomplete;
 
-// CHECK:STDERR: fail_incomplete_element.carbon:[[@LINE+6]]:8: error: variable has incomplete type `[Incomplete; 1]` [IncompleteTypeInVarDecl]
+// CHECK:STDERR: fail_incomplete_element.carbon:[[@LINE+7]]:8: error: variable has incomplete type `[Incomplete; 1]` [IncompleteTypeInVarDecl]
 // CHECK:STDERR: var a: [Incomplete; 1];
 // CHECK:STDERR:        ^~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_incomplete_element.carbon:[[@LINE-5]]:1: note: class was forward declared here [ClassForwardDeclaredHere]
 // CHECK:STDERR: class Incomplete;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 var a: [Incomplete; 1];
 
 var p: Incomplete* = &a[0];
diff --git a/toolchain/check/testdata/array/fail_invalid_type.carbon b/toolchain/check/testdata/array/fail_invalid_type.carbon
index b6a4d3695c2a..78c21511539d 100644
--- a/toolchain/check/testdata/array/fail_invalid_type.carbon
+++ b/toolchain/check/testdata/array/fail_invalid_type.carbon
@@ -8,12 +8,13 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/array/fail_invalid_type.carbon
 
-// CHECK:STDERR: fail_invalid_type.carbon:[[@LINE+6]]:9: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_invalid_type.carbon:[[@LINE+7]]:9: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var a: [1; 1];
 // CHECK:STDERR:         ^
-// CHECK:STDERR: fail_invalid_type.carbon:[[@LINE+3]]:9: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
+// CHECK:STDERR: fail_invalid_type.carbon:[[@LINE+4]]:9: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
 // CHECK:STDERR: var a: [1; 1];
 // CHECK:STDERR:         ^
+// CHECK:STDERR:
 var a: [1; 1];
 
 // CHECK:STDOUT: --- fail_invalid_type.carbon
diff --git a/toolchain/check/testdata/array/fail_out_of_bound.carbon b/toolchain/check/testdata/array/fail_out_of_bound.carbon
index 133183bf89be..955407191a07 100644
--- a/toolchain/check/testdata/array/fail_out_of_bound.carbon
+++ b/toolchain/check/testdata/array/fail_out_of_bound.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/array/fail_out_of_bound.carbon
 
-// CHECK:STDERR: fail_out_of_bound.carbon:[[@LINE+3]]:19: error: cannot initialize array of 1 element from 3 initializers [ArrayInitFromLiteralArgCountMismatch]
+// CHECK:STDERR: fail_out_of_bound.carbon:[[@LINE+4]]:19: error: cannot initialize array of 1 element from 3 initializers [ArrayInitFromLiteralArgCountMismatch]
 // CHECK:STDERR: var a: [i32; 1] = (1, 2, 3);
 // CHECK:STDERR:                   ^~~~~~~~~
+// CHECK:STDERR:
 var a: [i32; 1] = (1, 2, 3);
 
 // CHECK:STDOUT: --- fail_out_of_bound.carbon
@@ -48,7 +49,7 @@ var a: [i32; 1] = (1, 2, 3);
 // CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [template = constants.%int_1]
 // CHECK:STDOUT:   %int_2: Core.IntLiteral = int_value 2 [template = constants.%int_2]
 // CHECK:STDOUT:   %int_3: Core.IntLiteral = int_value 3 [template = constants.%int_3]
-// CHECK:STDOUT:   %.loc14: %tuple.type = tuple_literal (%int_1, %int_2, %int_3)
+// CHECK:STDOUT:   %.loc15: %tuple.type = tuple_literal (%int_1, %int_2, %int_3)
 // CHECK:STDOUT:   assign file.%a.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/array/fail_out_of_bound_non_literal.carbon b/toolchain/check/testdata/array/fail_out_of_bound_non_literal.carbon
index 123be410b791..fc3d0c7fda31 100644
--- a/toolchain/check/testdata/array/fail_out_of_bound_non_literal.carbon
+++ b/toolchain/check/testdata/array/fail_out_of_bound_non_literal.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/array/fail_out_of_bound_non_literal.carbon
 
 var a: [i32; 3] = (1, 2, 3);
-// CHECK:STDERR: fail_out_of_bound_non_literal.carbon:[[@LINE+3]]:16: error: array index `3` is past the end of type `[i32; 3]` [ArrayIndexOutOfBounds]
+// CHECK:STDERR: fail_out_of_bound_non_literal.carbon:[[@LINE+4]]:16: error: array index `3` is past the end of type `[i32; 3]` [ArrayIndexOutOfBounds]
 // CHECK:STDERR: var b: i32 = a[{.index = 3}.index];
 // CHECK:STDERR:                ^~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 var b: i32 = a[{.index = 3}.index];
 
 // CHECK:STDOUT: --- fail_out_of_bound_non_literal.carbon
@@ -99,22 +100,22 @@ var b: i32 = a[{.index = 3}.index];
 // CHECK:STDOUT:   %.loc11_28: init %array_type = converted %.loc11_27.1, %.loc11_27.11 [template = constants.%array]
 // CHECK:STDOUT:   assign file.%a.var, %.loc11_28
 // CHECK:STDOUT:   %a.ref: ref %array_type = name_ref a, file.%a
-// CHECK:STDOUT:   %int_3.loc15: Core.IntLiteral = int_value 3 [template = constants.%int_3.1ba]
-// CHECK:STDOUT:   %.loc15_27.1: %struct_type.index = struct_literal (%int_3.loc15)
-// CHECK:STDOUT:   %struct: %struct_type.index = struct_value (%int_3.loc15) [template = constants.%struct]
-// CHECK:STDOUT:   %.loc15_27.2: %struct_type.index = converted %.loc15_27.1, %struct [template = constants.%struct]
-// CHECK:STDOUT:   %.loc15_28.1: Core.IntLiteral = struct_access %.loc15_27.2, element0 [template = constants.%int_3.1ba]
+// CHECK:STDOUT:   %int_3.loc16: Core.IntLiteral = int_value 3 [template = constants.%int_3.1ba]
+// CHECK:STDOUT:   %.loc16_27.1: %struct_type.index = struct_literal (%int_3.loc16)
+// CHECK:STDOUT:   %struct: %struct_type.index = struct_value (%int_3.loc16) [template = constants.%struct]
+// CHECK:STDOUT:   %.loc16_27.2: %struct_type.index = converted %.loc16_27.1, %struct [template = constants.%struct]
+// CHECK:STDOUT:   %.loc16_28.1: Core.IntLiteral = struct_access %.loc16_27.2, element0 [template = constants.%int_3.1ba]
 // CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [template = constants.%int_32]
 // CHECK:STDOUT:   %i32: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
-// CHECK:STDOUT:   %impl.elem0.loc15: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
-// CHECK:STDOUT:   %Convert.bound.loc15: <bound method> = bound_method %.loc15_28.1, %impl.elem0.loc15 [template = constants.%Convert.bound.b30]
-// CHECK:STDOUT:   %Convert.specific_fn.loc15: <specific function> = specific_function %Convert.bound.loc15, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.b42]
-// CHECK:STDOUT:   %int.convert_checked.loc15: init %i32 = call %Convert.specific_fn.loc15(%.loc15_28.1) [template = constants.%int_3.822]
-// CHECK:STDOUT:   %.loc15_28.2: %i32 = value_of_initializer %int.convert_checked.loc15 [template = constants.%int_3.822]
-// CHECK:STDOUT:   %.loc15_28.3: %i32 = converted %.loc15_28.1, %.loc15_28.2 [template = constants.%int_3.822]
-// CHECK:STDOUT:   %.loc15_34.1: ref %i32 = array_index %a.ref, %.loc15_28.3 [template = <error>]
-// CHECK:STDOUT:   %.loc15_34.2: %i32 = bind_value %.loc15_34.1
-// CHECK:STDOUT:   assign file.%b.var, %.loc15_34.2
+// CHECK:STDOUT:   %impl.elem0.loc16: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
+// CHECK:STDOUT:   %Convert.bound.loc16: <bound method> = bound_method %.loc16_28.1, %impl.elem0.loc16 [template = constants.%Convert.bound.b30]
+// CHECK:STDOUT:   %Convert.specific_fn.loc16: <specific function> = specific_function %Convert.bound.loc16, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.b42]
+// CHECK:STDOUT:   %int.convert_checked.loc16: init %i32 = call %Convert.specific_fn.loc16(%.loc16_28.1) [template = constants.%int_3.822]
+// CHECK:STDOUT:   %.loc16_28.2: %i32 = value_of_initializer %int.convert_checked.loc16 [template = constants.%int_3.822]
+// CHECK:STDOUT:   %.loc16_28.3: %i32 = converted %.loc16_28.1, %.loc16_28.2 [template = constants.%int_3.822]
+// CHECK:STDOUT:   %.loc16_34.1: ref %i32 = array_index %a.ref, %.loc16_28.3 [template = <error>]
+// CHECK:STDOUT:   %.loc16_34.2: %i32 = bind_value %.loc16_34.1
+// CHECK:STDOUT:   assign file.%b.var, %.loc16_34.2
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/array/fail_type_mismatch.carbon b/toolchain/check/testdata/array/fail_type_mismatch.carbon
index 8f74e5056204..2301e6be2ae5 100644
--- a/toolchain/check/testdata/array/fail_type_mismatch.carbon
+++ b/toolchain/check/testdata/array/fail_type_mismatch.carbon
@@ -34,9 +34,10 @@ var b: [i32; 3] = t1;
 var c: [i32; 3] = (1, 2);
 
 var t2: (i32, i32);
-// CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+3]]:19: error: cannot initialize array of 3 elements from tuple with 2 elements [ArrayInitFromExprArgCountMismatch]
+// CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+4]]:19: error: cannot initialize array of 3 elements from tuple with 2 elements [ArrayInitFromExprArgCountMismatch]
 // CHECK:STDERR: var d: [i32; 3] = t2;
 // CHECK:STDERR:                   ^~
+// CHECK:STDERR:
 var d: [i32; 3] = t2;
 
 // CHECK:STDOUT: --- fail_type_mismatch.carbon
diff --git a/toolchain/check/testdata/array/fail_undefined_bound.carbon b/toolchain/check/testdata/array/fail_undefined_bound.carbon
index 22e33061941b..83a0e21e61fb 100644
--- a/toolchain/check/testdata/array/fail_undefined_bound.carbon
+++ b/toolchain/check/testdata/array/fail_undefined_bound.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/array/fail_undefined_bound.carbon
 
-// CHECK:STDERR: fail_undefined_bound.carbon:[[@LINE+3]]:8: error: semantics TODO: `HandleArrayExprWithoutBounds` [SemanticsTodo]
+// CHECK:STDERR: fail_undefined_bound.carbon:[[@LINE+4]]:8: error: semantics TODO: `HandleArrayExprWithoutBounds` [SemanticsTodo]
 // CHECK:STDERR: var a: [i32; ];
 // CHECK:STDERR:        ^~~~~~~
+// CHECK:STDERR:
 var a: [i32; ];
 
 // CHECK:STDOUT: --- fail_undefined_bound.carbon
diff --git a/toolchain/check/testdata/array/init_dependent_bound.carbon b/toolchain/check/testdata/array/init_dependent_bound.carbon
index 4266f6ab486b..e1591a5b7483 100644
--- a/toolchain/check/testdata/array/init_dependent_bound.carbon
+++ b/toolchain/check/testdata/array/init_dependent_bound.carbon
@@ -25,9 +25,10 @@ fn F(N:! i32) {
 library "[[@TEST_NAME]]";
 
 // TODO: This should be valid.
-// CHECK:STDERR: fail_todo_init_template_dependent_bound.carbon:[[@LINE+3]]:6: error: semantics TODO: `HandleTemplate` [SemanticsTodo]
+// CHECK:STDERR: fail_todo_init_template_dependent_bound.carbon:[[@LINE+4]]:6: error: semantics TODO: `HandleTemplate` [SemanticsTodo]
 // CHECK:STDERR: fn G(template N:! i32) {
 // CHECK:STDERR:      ^~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 fn G(template N:! i32) {
   var arr: [i32; N] = (1, 2, 3);
 }
diff --git a/toolchain/check/testdata/as/adapter_conversion.carbon b/toolchain/check/testdata/as/adapter_conversion.carbon
index a5c896d78758..7009182c6e07 100644
--- a/toolchain/check/testdata/as/adapter_conversion.carbon
+++ b/toolchain/check/testdata/as/adapter_conversion.carbon
@@ -154,12 +154,13 @@ class B {
 // We do not try to implicitly convert from the first operand of `as` to the
 // adapted type of the second operand.
 
-// CHECK:STDERR: fail_adapt_init_from_struct.carbon:[[@LINE+6]]:12: error: cannot convert from `{.x: Core.IntLiteral}` to `B` with `as` [ExplicitAsConversionFailure]
+// CHECK:STDERR: fail_adapt_init_from_struct.carbon:[[@LINE+7]]:12: error: cannot convert from `{.x: Core.IntLiteral}` to `B` with `as` [ExplicitAsConversionFailure]
 // CHECK:STDERR: var b: B = {.x = 1} as B;
 // CHECK:STDERR:            ^~~~~~~~~~~~~
-// CHECK:STDERR: fail_adapt_init_from_struct.carbon:[[@LINE+3]]:12: note: type `{.x: Core.IntLiteral}` does not implement interface `Core.As(B)` [MissingImplInMemberAccessNote]
+// CHECK:STDERR: fail_adapt_init_from_struct.carbon:[[@LINE+4]]:12: note: type `{.x: Core.IntLiteral}` does not implement interface `Core.As(B)` [MissingImplInMemberAccessNote]
 // CHECK:STDERR: var b: B = {.x = 1} as B;
 // CHECK:STDERR:            ^~~~~~~~~~~~~
+// CHECK:STDERR:
 var b: B = {.x = 1} as B;
 
 // CHECK:STDOUT: --- adapt_class.carbon
@@ -861,9 +862,9 @@ var b: B = {.x = 1} as B;
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [template = constants.%int_1]
-// CHECK:STDOUT:   %.loc21_19: %struct_type.x.c96 = struct_literal (%int_1)
+// CHECK:STDOUT:   %.loc22_19: %struct_type.x.c96 = struct_literal (%int_1)
 // CHECK:STDOUT:   %B.ref: type = name_ref B, file.%B.decl [template = constants.%B]
-// CHECK:STDOUT:   %.loc21_21: %B = converted %.loc21_19, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc22_21: %B = converted %.loc22_19, <error> [template = <error>]
 // CHECK:STDOUT:   assign file.%b.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/as/fail_no_conversion.carbon b/toolchain/check/testdata/as/fail_no_conversion.carbon
index 00b9017df124..e2f666594204 100644
--- a/toolchain/check/testdata/as/fail_no_conversion.carbon
+++ b/toolchain/check/testdata/as/fail_no_conversion.carbon
@@ -8,12 +8,13 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/as/fail_no_conversion.carbon
 
-// CHECK:STDERR: fail_no_conversion.carbon:[[@LINE+6]]:21: error: cannot convert from `Core.IntLiteral` to `(i32, i32)` with `as` [ExplicitAsConversionFailure]
+// CHECK:STDERR: fail_no_conversion.carbon:[[@LINE+7]]:21: error: cannot convert from `Core.IntLiteral` to `(i32, i32)` with `as` [ExplicitAsConversionFailure]
 // CHECK:STDERR: let n: (i32, i32) = 1 as (i32, i32);
 // CHECK:STDERR:                     ^~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_no_conversion.carbon:[[@LINE+3]]:21: note: type `Core.IntLiteral` does not implement interface `Core.As((i32, i32))` [MissingImplInMemberAccessNote]
+// CHECK:STDERR: fail_no_conversion.carbon:[[@LINE+4]]:21: note: type `Core.IntLiteral` does not implement interface `Core.As((i32, i32))` [MissingImplInMemberAccessNote]
 // CHECK:STDERR: let n: (i32, i32) = 1 as (i32, i32);
 // CHECK:STDERR:                     ^~~~~~~~~~~~~~~
+// CHECK:STDERR:
 let n: (i32, i32) = 1 as (i32, i32);
 
 // CHECK:STDOUT: --- fail_no_conversion.carbon
@@ -46,14 +47,14 @@ let n: (i32, i32) = 1 as (i32, i32);
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [template = constants.%int_1]
-// CHECK:STDOUT:   %int_32.loc17_27: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:   %i32.loc17_27: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
-// CHECK:STDOUT:   %int_32.loc17_32: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:   %i32.loc17_32: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
-// CHECK:STDOUT:   %.loc17_35.1: %tuple.type.24b = tuple_literal (%i32.loc17_27, %i32.loc17_32)
-// CHECK:STDOUT:   %.loc17_35.2: type = converted %.loc17_35.1, constants.%tuple.type.d07 [template = constants.%tuple.type.d07]
-// CHECK:STDOUT:   %.loc17_23: %tuple.type.d07 = converted %int_1, <error> [template = <error>]
-// CHECK:STDOUT:   %tuple.elem0: %i32 = tuple_access %.loc17_23, element0 [template = <error>]
+// CHECK:STDOUT:   %int_32.loc18_27: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:   %i32.loc18_27: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:   %int_32.loc18_32: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:   %i32.loc18_32: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:   %.loc18_35.1: %tuple.type.24b = tuple_literal (%i32.loc18_27, %i32.loc18_32)
+// CHECK:STDOUT:   %.loc18_35.2: type = converted %.loc18_35.1, constants.%tuple.type.d07 [template = constants.%tuple.type.d07]
+// CHECK:STDOUT:   %.loc18_23: %tuple.type.d07 = converted %int_1, <error> [template = <error>]
+// CHECK:STDOUT:   %tuple.elem0: %i32 = tuple_access %.loc18_23, element0 [template = <error>]
 // CHECK:STDOUT:   %n: %tuple.type.d07 = bind_name n, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/as/fail_not_type.carbon b/toolchain/check/testdata/as/fail_not_type.carbon
index f34d13cdd91a..b0e509487ebd 100644
--- a/toolchain/check/testdata/as/fail_not_type.carbon
+++ b/toolchain/check/testdata/as/fail_not_type.carbon
@@ -8,12 +8,13 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/as/fail_not_type.carbon
 
-// CHECK:STDERR: fail_not_type.carbon:[[@LINE+6]]:19: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_not_type.carbon:[[@LINE+7]]:19: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
 // CHECK:STDERR: let n: i32 = 1 as 2;
 // CHECK:STDERR:                   ^
-// CHECK:STDERR: fail_not_type.carbon:[[@LINE+3]]:19: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
+// CHECK:STDERR: fail_not_type.carbon:[[@LINE+4]]:19: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
 // CHECK:STDERR: let n: i32 = 1 as 2;
 // CHECK:STDERR:                   ^
+// CHECK:STDERR:
 let n: i32 = 1 as 2;
 
 // CHECK:STDOUT: --- fail_not_type.carbon
@@ -46,7 +47,7 @@ let n: i32 = 1 as 2;
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [template = constants.%int_1]
 // CHECK:STDOUT:   %int_2: Core.IntLiteral = int_value 2 [template = constants.%int_2]
-// CHECK:STDOUT:   %.loc17: type = converted %int_2, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc18: type = converted %int_2, <error> [template = <error>]
 // CHECK:STDOUT:   %n: %i32 = bind_name n, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/basics/fail_bad_run.carbon b/toolchain/check/testdata/basics/fail_bad_run.carbon
index 3b1379be7ccc..860bfde2293b 100644
--- a/toolchain/check/testdata/basics/fail_bad_run.carbon
+++ b/toolchain/check/testdata/basics/fail_bad_run.carbon
@@ -8,13 +8,14 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/fail_bad_run.carbon
 
-// CHECK:STDERR: fail_bad_run.carbon:[[@LINE+7]]:1: error: invalid signature for `Main.Run` function; expected `fn ()` or `fn () -> i32` [InvalidMainRunSignature]
+// CHECK:STDERR: fail_bad_run.carbon:[[@LINE+8]]:1: error: invalid signature for `Main.Run` function; expected `fn ()` or `fn () -> i32` [InvalidMainRunSignature]
 // CHECK:STDERR: fn Run() -> String {}
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_bad_run.carbon:[[@LINE+3]]:21: error: missing `return` at end of function with declared return type [MissingReturnStatement]
+// CHECK:STDERR: fail_bad_run.carbon:[[@LINE+4]]:21: error: missing `return` at end of function with declared return type [MissingReturnStatement]
 // CHECK:STDERR: fn Run() -> String {}
 // CHECK:STDERR:                     ^
+// CHECK:STDERR:
 fn Run() -> String {}
 
 // CHECK:STDOUT: --- fail_bad_run.carbon
diff --git a/toolchain/check/testdata/basics/fail_bad_run_2.carbon b/toolchain/check/testdata/basics/fail_bad_run_2.carbon
index 70f0ed8e4e9d..5fa43b060ef5 100644
--- a/toolchain/check/testdata/basics/fail_bad_run_2.carbon
+++ b/toolchain/check/testdata/basics/fail_bad_run_2.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/fail_bad_run_2.carbon
 
-// CHECK:STDERR: fail_bad_run_2.carbon:[[@LINE+3]]:1: error: invalid signature for `Main.Run` function; expected `fn ()` or `fn () -> i32` [InvalidMainRunSignature]
+// CHECK:STDERR: fail_bad_run_2.carbon:[[@LINE+4]]:1: error: invalid signature for `Main.Run` function; expected `fn ()` or `fn () -> i32` [InvalidMainRunSignature]
 // CHECK:STDERR: fn Run(n: i32) {}
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 fn Run(n: i32) {}
 
 // CHECK:STDOUT: --- fail_bad_run_2.carbon
@@ -41,7 +42,7 @@ fn Run(n: i32) {}
 // CHECK:STDOUT:     %n.param_patt: %i32 = value_param_pattern %n.patt, runtime_param0
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %n.param: %i32 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc14: type = splice_block %i32 [template = constants.%i32] {
+// CHECK:STDOUT:     %.loc15: type = splice_block %i32 [template = constants.%i32] {
 // CHECK:STDOUT:       %int_32: Core.IntLiteral = int_value 32 [template = constants.%int_32]
 // CHECK:STDOUT:       %i32: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
 // CHECK:STDOUT:     }
diff --git a/toolchain/check/testdata/basics/fail_non_type_as_type.carbon b/toolchain/check/testdata/basics/fail_non_type_as_type.carbon
index b902b468890f..15b53e1135ad 100644
--- a/toolchain/check/testdata/basics/fail_non_type_as_type.carbon
+++ b/toolchain/check/testdata/basics/fail_non_type_as_type.carbon
@@ -8,12 +8,13 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/fail_non_type_as_type.carbon
 
-// CHECK:STDERR: fail_non_type_as_type.carbon:[[@LINE+6]]:1: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_non_type_as_type.carbon:[[@LINE+7]]:1: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var x: type = 42;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_non_type_as_type.carbon:[[@LINE+3]]:1: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
+// CHECK:STDERR: fail_non_type_as_type.carbon:[[@LINE+4]]:1: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
 // CHECK:STDERR: var x: type = 42;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 var x: type = 42;
 
 // CHECK:STDOUT: --- fail_non_type_as_type.carbon
@@ -43,7 +44,7 @@ var x: type = 42;
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %int_42: Core.IntLiteral = int_value 42 [template = constants.%int_42]
-// CHECK:STDOUT:   %.loc17: type = converted %int_42, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc18: type = converted %int_42, <error> [template = <error>]
 // CHECK:STDOUT:   assign file.%x.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/basics/fail_numeric_literal_overflow.carbon b/toolchain/check/testdata/basics/fail_numeric_literal_overflow.carbon
index 1fd5918b0696..2b3f3cc18377 100644
--- a/toolchain/check/testdata/basics/fail_numeric_literal_overflow.carbon
+++ b/toolchain/check/testdata/basics/fail_numeric_literal_overflow.carbon
@@ -32,9 +32,10 @@ let c: i32 = 0x8000_0000;
 // CHECK:STDERR:
 let d: f64 = 39999999999999999993.0e3;
 
-// CHECK:STDERR: fail_numeric_literal_overflow.carbon:[[@LINE+3]]:14: error: real exponent with value 39999999999999999992 does not fit in i64 [RealExponentTooLargeForI64]
+// CHECK:STDERR: fail_numeric_literal_overflow.carbon:[[@LINE+4]]:14: error: real exponent with value 39999999999999999992 does not fit in i64 [RealExponentTooLargeForI64]
 // CHECK:STDERR: let e: f64 = 5.0e39999999999999999993;
 // CHECK:STDERR:              ^~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 let e: f64 = 5.0e39999999999999999993;
 
 // CHECK:STDOUT: --- fail_numeric_literal_overflow.carbon
diff --git a/toolchain/check/testdata/basics/no_prelude/fail_name_lookup.carbon b/toolchain/check/testdata/basics/no_prelude/fail_name_lookup.carbon
index 4f9d3d2f8251..c9934da1abcc 100644
--- a/toolchain/check/testdata/basics/no_prelude/fail_name_lookup.carbon
+++ b/toolchain/check/testdata/basics/no_prelude/fail_name_lookup.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/no_prelude/fail_name_lookup.carbon
 
 fn Main() {
-  // CHECK:STDERR: fail_name_lookup.carbon:[[@LINE+3]]:3: error: name `x` not found [NameNotFound]
+  // CHECK:STDERR: fail_name_lookup.carbon:[[@LINE+4]]:3: error: name `x` not found [NameNotFound]
   // CHECK:STDERR:   x;
   // CHECK:STDERR:   ^
+  // CHECK:STDERR:
   x;
 }
 
diff --git a/toolchain/check/testdata/basics/no_prelude/fail_qualifier_unsupported.carbon b/toolchain/check/testdata/basics/no_prelude/fail_qualifier_unsupported.carbon
index 78a791029911..a59d25c0f099 100644
--- a/toolchain/check/testdata/basics/no_prelude/fail_qualifier_unsupported.carbon
+++ b/toolchain/check/testdata/basics/no_prelude/fail_qualifier_unsupported.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/no_prelude/fail_qualifier_unsupported.carbon
 
-// CHECK:STDERR: fail_qualifier_unsupported.carbon:[[@LINE+3]]:10: error: type `bool` does not support qualified expressions [QualifiedExprUnsupported]
+// CHECK:STDERR: fail_qualifier_unsupported.carbon:[[@LINE+4]]:10: error: type `bool` does not support qualified expressions [QualifiedExprUnsupported]
 // CHECK:STDERR: fn F() { true.b; }
 // CHECK:STDERR:          ^~~~~~
+// CHECK:STDERR:
 fn F() { true.b; }
 
 // CHECK:STDOUT: --- fail_qualifier_unsupported.carbon
diff --git a/toolchain/check/testdata/basics/type_literals.carbon b/toolchain/check/testdata/basics/type_literals.carbon
index 414fbc855f13..b24587b33e42 100644
--- a/toolchain/check/testdata/basics/type_literals.carbon
+++ b/toolchain/check/testdata/basics/type_literals.carbon
@@ -118,9 +118,10 @@ var test_f1000000000000: f1000000000000;
 library "[[@TEST_NAME]]";
 
 // TODO: Some or all of these should eventually work.
-// CHECK:STDERR: fail_fN_todo_unsupported.carbon:[[@LINE+3]]:15: error: semantics TODO: `Currently only f64 is allowed` [SemanticsTodo]
+// CHECK:STDERR: fail_fN_todo_unsupported.carbon:[[@LINE+4]]:15: error: semantics TODO: `Currently only f64 is allowed` [SemanticsTodo]
 // CHECK:STDERR: var test_f16: f16;
 // CHECK:STDERR:               ^~~
+// CHECK:STDERR:
 var test_f16: f16;
 var test_f32: f32;
 var test_f128: f128;
diff --git a/toolchain/check/testdata/builtins/float/add.carbon b/toolchain/check/testdata/builtins/float/add.carbon
index d3213233bb15..1be6b7ff1fd6 100644
--- a/toolchain/check/testdata/builtins/float/add.carbon
+++ b/toolchain/check/testdata/builtins/float/add.carbon
@@ -32,9 +32,10 @@ fn TooFew(a: f64) -> f64 = "float.add";
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
 fn TooMany(a: f64, b: f64, c: f64) -> f64 = "float.add";
-// CHECK:STDERR: fail_bad_decl.carbon:[[@LINE+3]]:1: error: invalid signature for builtin function "float.add" [InvalidBuiltinSignature]
+// CHECK:STDERR: fail_bad_decl.carbon:[[@LINE+4]]:1: error: invalid signature for builtin function "float.add" [InvalidBuiltinSignature]
 // CHECK:STDERR: fn BadReturnType(a: f64, b: f64) -> bool = "float.add";
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 fn BadReturnType(a: f64, b: f64) -> bool = "float.add";
 fn JustRight(a: f64, b: f64) -> f64 = "float.add";
 
@@ -286,22 +287,22 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:     %return.param_patt: bool = out_param_pattern %return.patt, runtime_param2
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %bool.make_type: init type = call constants.%Bool() [template = bool]
-// CHECK:STDOUT:     %.loc17_37.1: type = value_of_initializer %bool.make_type [template = bool]
-// CHECK:STDOUT:     %.loc17_37.2: type = converted %bool.make_type, %.loc17_37.1 [template = bool]
+// CHECK:STDOUT:     %.loc18_37.1: type = value_of_initializer %bool.make_type [template = bool]
+// CHECK:STDOUT:     %.loc18_37.2: type = converted %bool.make_type, %.loc18_37.1 [template = bool]
 // CHECK:STDOUT:     %a.param: f64 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc17_21.1: type = splice_block %.loc17_21.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc17_21: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc17_21: init type = call constants.%Float(%int_64.loc17_21) [template = f64]
-// CHECK:STDOUT:       %.loc17_21.2: type = value_of_initializer %float.make_type.loc17_21 [template = f64]
-// CHECK:STDOUT:       %.loc17_21.3: type = converted %float.make_type.loc17_21, %.loc17_21.2 [template = f64]
+// CHECK:STDOUT:     %.loc18_21.1: type = splice_block %.loc18_21.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc18_21: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc18_21: init type = call constants.%Float(%int_64.loc18_21) [template = f64]
+// CHECK:STDOUT:       %.loc18_21.2: type = value_of_initializer %float.make_type.loc18_21 [template = f64]
+// CHECK:STDOUT:       %.loc18_21.3: type = converted %float.make_type.loc18_21, %.loc18_21.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: f64 = bind_name a, %a.param
 // CHECK:STDOUT:     %b.param: f64 = value_param runtime_param1
-// CHECK:STDOUT:     %.loc17_29.1: type = splice_block %.loc17_29.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc17_29: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc17_29: init type = call constants.%Float(%int_64.loc17_29) [template = f64]
-// CHECK:STDOUT:       %.loc17_29.2: type = value_of_initializer %float.make_type.loc17_29 [template = f64]
-// CHECK:STDOUT:       %.loc17_29.3: type = converted %float.make_type.loc17_29, %.loc17_29.2 [template = f64]
+// CHECK:STDOUT:     %.loc18_29.1: type = splice_block %.loc18_29.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc18_29: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc18_29: init type = call constants.%Float(%int_64.loc18_29) [template = f64]
+// CHECK:STDOUT:       %.loc18_29.2: type = value_of_initializer %float.make_type.loc18_29 [template = f64]
+// CHECK:STDOUT:       %.loc18_29.3: type = converted %float.make_type.loc18_29, %.loc18_29.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %b: f64 = bind_name b, %b.param
 // CHECK:STDOUT:     %return.param: ref bool = out_param runtime_param2
@@ -315,24 +316,24 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:     %return.patt: f64 = return_slot_pattern
 // CHECK:STDOUT:     %return.param_patt: f64 = out_param_pattern %return.patt, runtime_param2
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %int_64.loc18_33: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:     %float.make_type.loc18_33: init type = call constants.%Float(%int_64.loc18_33) [template = f64]
-// CHECK:STDOUT:     %.loc18_33.1: type = value_of_initializer %float.make_type.loc18_33 [template = f64]
-// CHECK:STDOUT:     %.loc18_33.2: type = converted %float.make_type.loc18_33, %.loc18_33.1 [template = f64]
+// CHECK:STDOUT:     %int_64.loc19_33: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:     %float.make_type.loc19_33: init type = call constants.%Float(%int_64.loc19_33) [template = f64]
+// CHECK:STDOUT:     %.loc19_33.1: type = value_of_initializer %float.make_type.loc19_33 [template = f64]
+// CHECK:STDOUT:     %.loc19_33.2: type = converted %float.make_type.loc19_33, %.loc19_33.1 [template = f64]
 // CHECK:STDOUT:     %a.param: f64 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc18_17.1: type = splice_block %.loc18_17.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc18_17: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc18_17: init type = call constants.%Float(%int_64.loc18_17) [template = f64]
-// CHECK:STDOUT:       %.loc18_17.2: type = value_of_initializer %float.make_type.loc18_17 [template = f64]
-// CHECK:STDOUT:       %.loc18_17.3: type = converted %float.make_type.loc18_17, %.loc18_17.2 [template = f64]
+// CHECK:STDOUT:     %.loc19_17.1: type = splice_block %.loc19_17.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc19_17: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc19_17: init type = call constants.%Float(%int_64.loc19_17) [template = f64]
+// CHECK:STDOUT:       %.loc19_17.2: type = value_of_initializer %float.make_type.loc19_17 [template = f64]
+// CHECK:STDOUT:       %.loc19_17.3: type = converted %float.make_type.loc19_17, %.loc19_17.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: f64 = bind_name a, %a.param
 // CHECK:STDOUT:     %b.param: f64 = value_param runtime_param1
-// CHECK:STDOUT:     %.loc18_25.1: type = splice_block %.loc18_25.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc18_25: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc18_25: init type = call constants.%Float(%int_64.loc18_25) [template = f64]
-// CHECK:STDOUT:       %.loc18_25.2: type = value_of_initializer %float.make_type.loc18_25 [template = f64]
-// CHECK:STDOUT:       %.loc18_25.3: type = converted %float.make_type.loc18_25, %.loc18_25.2 [template = f64]
+// CHECK:STDOUT:     %.loc19_25.1: type = splice_block %.loc19_25.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc19_25: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc19_25: init type = call constants.%Float(%int_64.loc19_25) [template = f64]
+// CHECK:STDOUT:       %.loc19_25.2: type = value_of_initializer %float.make_type.loc19_25 [template = f64]
+// CHECK:STDOUT:       %.loc19_25.3: type = converted %float.make_type.loc19_25, %.loc19_25.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %b: f64 = bind_name b, %b.param
 // CHECK:STDOUT:     %return.param: ref f64 = out_param runtime_param2
@@ -344,16 +345,16 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:     %return.patt: f64 = return_slot_pattern
 // CHECK:STDOUT:     %return.param_patt: f64 = out_param_pattern %return.patt, runtime_param1
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %int_64.loc20_40: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:     %float.make_type.loc20_40: init type = call constants.%Float(%int_64.loc20_40) [template = f64]
-// CHECK:STDOUT:     %.loc20_40.1: type = value_of_initializer %float.make_type.loc20_40 [template = f64]
-// CHECK:STDOUT:     %.loc20_40.2: type = converted %float.make_type.loc20_40, %.loc20_40.1 [template = f64]
+// CHECK:STDOUT:     %int_64.loc21_40: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:     %float.make_type.loc21_40: init type = call constants.%Float(%int_64.loc21_40) [template = f64]
+// CHECK:STDOUT:     %.loc21_40.1: type = value_of_initializer %float.make_type.loc21_40 [template = f64]
+// CHECK:STDOUT:     %.loc21_40.2: type = converted %float.make_type.loc21_40, %.loc21_40.1 [template = f64]
 // CHECK:STDOUT:     %a.param: f64 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc20_32.1: type = splice_block %.loc20_32.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc20_32: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc20_32: init type = call constants.%Float(%int_64.loc20_32) [template = f64]
-// CHECK:STDOUT:       %.loc20_32.2: type = value_of_initializer %float.make_type.loc20_32 [template = f64]
-// CHECK:STDOUT:       %.loc20_32.3: type = converted %float.make_type.loc20_32, %.loc20_32.2 [template = f64]
+// CHECK:STDOUT:     %.loc21_32.1: type = splice_block %.loc21_32.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc21_32: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc21_32: init type = call constants.%Float(%int_64.loc21_32) [template = f64]
+// CHECK:STDOUT:       %.loc21_32.2: type = value_of_initializer %float.make_type.loc21_32 [template = f64]
+// CHECK:STDOUT:       %.loc21_32.3: type = converted %float.make_type.loc21_32, %.loc21_32.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: f64 = bind_name a, %a.param
 // CHECK:STDOUT:     %return.param: ref f64 = out_param runtime_param1
@@ -369,32 +370,32 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:     %return.patt: f64 = return_slot_pattern
 // CHECK:STDOUT:     %return.param_patt: f64 = out_param_pattern %return.patt, runtime_param3
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %int_64.loc24_57: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:     %float.make_type.loc24_57: init type = call constants.%Float(%int_64.loc24_57) [template = f64]
-// CHECK:STDOUT:     %.loc24_57.1: type = value_of_initializer %float.make_type.loc24_57 [template = f64]
-// CHECK:STDOUT:     %.loc24_57.2: type = converted %float.make_type.loc24_57, %.loc24_57.1 [template = f64]
+// CHECK:STDOUT:     %int_64.loc25_57: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:     %float.make_type.loc25_57: init type = call constants.%Float(%int_64.loc25_57) [template = f64]
+// CHECK:STDOUT:     %.loc25_57.1: type = value_of_initializer %float.make_type.loc25_57 [template = f64]
+// CHECK:STDOUT:     %.loc25_57.2: type = converted %float.make_type.loc25_57, %.loc25_57.1 [template = f64]
 // CHECK:STDOUT:     %a.param: f64 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc24_33.1: type = splice_block %.loc24_33.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc24_33: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc24_33: init type = call constants.%Float(%int_64.loc24_33) [template = f64]
-// CHECK:STDOUT:       %.loc24_33.2: type = value_of_initializer %float.make_type.loc24_33 [template = f64]
-// CHECK:STDOUT:       %.loc24_33.3: type = converted %float.make_type.loc24_33, %.loc24_33.2 [template = f64]
+// CHECK:STDOUT:     %.loc25_33.1: type = splice_block %.loc25_33.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc25_33: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc25_33: init type = call constants.%Float(%int_64.loc25_33) [template = f64]
+// CHECK:STDOUT:       %.loc25_33.2: type = value_of_initializer %float.make_type.loc25_33 [template = f64]
+// CHECK:STDOUT:       %.loc25_33.3: type = converted %float.make_type.loc25_33, %.loc25_33.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: f64 = bind_name a, %a.param
 // CHECK:STDOUT:     %b.param: f64 = value_param runtime_param1
-// CHECK:STDOUT:     %.loc24_41.1: type = splice_block %.loc24_41.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc24_41: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc24_41: init type = call constants.%Float(%int_64.loc24_41) [template = f64]
-// CHECK:STDOUT:       %.loc24_41.2: type = value_of_initializer %float.make_type.loc24_41 [template = f64]
-// CHECK:STDOUT:       %.loc24_41.3: type = converted %float.make_type.loc24_41, %.loc24_41.2 [template = f64]
+// CHECK:STDOUT:     %.loc25_41.1: type = splice_block %.loc25_41.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc25_41: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc25_41: init type = call constants.%Float(%int_64.loc25_41) [template = f64]
+// CHECK:STDOUT:       %.loc25_41.2: type = value_of_initializer %float.make_type.loc25_41 [template = f64]
+// CHECK:STDOUT:       %.loc25_41.3: type = converted %float.make_type.loc25_41, %.loc25_41.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %b: f64 = bind_name b, %b.param
 // CHECK:STDOUT:     %c.param: f64 = value_param runtime_param2
-// CHECK:STDOUT:     %.loc24_49.1: type = splice_block %.loc24_49.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc24_49: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc24_49: init type = call constants.%Float(%int_64.loc24_49) [template = f64]
-// CHECK:STDOUT:       %.loc24_49.2: type = value_of_initializer %float.make_type.loc24_49 [template = f64]
-// CHECK:STDOUT:       %.loc24_49.3: type = converted %float.make_type.loc24_49, %.loc24_49.2 [template = f64]
+// CHECK:STDOUT:     %.loc25_49.1: type = splice_block %.loc25_49.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc25_49: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc25_49: init type = call constants.%Float(%int_64.loc25_49) [template = f64]
+// CHECK:STDOUT:       %.loc25_49.2: type = value_of_initializer %float.make_type.loc25_49 [template = f64]
+// CHECK:STDOUT:       %.loc25_49.3: type = converted %float.make_type.loc25_49, %.loc25_49.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %c: f64 = bind_name c, %c.param
 // CHECK:STDOUT:     %return.param: ref f64 = out_param runtime_param3
@@ -409,22 +410,22 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:     %return.param_patt: bool = out_param_pattern %return.patt, runtime_param2
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %bool.make_type: init type = call constants.%Bool() [template = bool]
-// CHECK:STDOUT:     %.loc28_55.1: type = value_of_initializer %bool.make_type [template = bool]
-// CHECK:STDOUT:     %.loc28_55.2: type = converted %bool.make_type, %.loc28_55.1 [template = bool]
+// CHECK:STDOUT:     %.loc29_55.1: type = value_of_initializer %bool.make_type [template = bool]
+// CHECK:STDOUT:     %.loc29_55.2: type = converted %bool.make_type, %.loc29_55.1 [template = bool]
 // CHECK:STDOUT:     %a.param: f64 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc28_39.1: type = splice_block %.loc28_39.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc28_39: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc28_39: init type = call constants.%Float(%int_64.loc28_39) [template = f64]
-// CHECK:STDOUT:       %.loc28_39.2: type = value_of_initializer %float.make_type.loc28_39 [template = f64]
-// CHECK:STDOUT:       %.loc28_39.3: type = converted %float.make_type.loc28_39, %.loc28_39.2 [template = f64]
+// CHECK:STDOUT:     %.loc29_39.1: type = splice_block %.loc29_39.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc29_39: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc29_39: init type = call constants.%Float(%int_64.loc29_39) [template = f64]
+// CHECK:STDOUT:       %.loc29_39.2: type = value_of_initializer %float.make_type.loc29_39 [template = f64]
+// CHECK:STDOUT:       %.loc29_39.3: type = converted %float.make_type.loc29_39, %.loc29_39.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: f64 = bind_name a, %a.param
 // CHECK:STDOUT:     %b.param: f64 = value_param runtime_param1
-// CHECK:STDOUT:     %.loc28_47.1: type = splice_block %.loc28_47.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc28_47: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc28_47: init type = call constants.%Float(%int_64.loc28_47) [template = f64]
-// CHECK:STDOUT:       %.loc28_47.2: type = value_of_initializer %float.make_type.loc28_47 [template = f64]
-// CHECK:STDOUT:       %.loc28_47.3: type = converted %float.make_type.loc28_47, %.loc28_47.2 [template = f64]
+// CHECK:STDOUT:     %.loc29_47.1: type = splice_block %.loc29_47.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc29_47: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc29_47: init type = call constants.%Float(%int_64.loc29_47) [template = f64]
+// CHECK:STDOUT:       %.loc29_47.2: type = value_of_initializer %float.make_type.loc29_47 [template = f64]
+// CHECK:STDOUT:       %.loc29_47.3: type = converted %float.make_type.loc29_47, %.loc29_47.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %b: f64 = bind_name b, %b.param
 // CHECK:STDOUT:     %return.param: ref bool = out_param runtime_param2
@@ -445,9 +446,9 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:   %TooFew.ref: %TooFew.type = name_ref TooFew, file.%TooFew.decl [template = constants.%TooFew]
 // CHECK:STDOUT:   %a.ref: f64 = name_ref a, %a
 // CHECK:STDOUT:   %TooFew.call: init f64 = call %TooFew.ref(%a.ref)
-// CHECK:STDOUT:   %.loc21_19.1: f64 = value_of_initializer %TooFew.call
-// CHECK:STDOUT:   %.loc21_19.2: f64 = converted %TooFew.call, %.loc21_19.1
-// CHECK:STDOUT:   return %.loc21_19.2
+// CHECK:STDOUT:   %.loc22_19.1: f64 = value_of_initializer %TooFew.call
+// CHECK:STDOUT:   %.loc22_19.2: f64 = converted %TooFew.call, %.loc22_19.1
+// CHECK:STDOUT:   return %.loc22_19.2
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @RuntimeCallIsValidTooMany(%a.param_patt: f64, %b.param_patt: f64, %c.param_patt: f64) -> f64 {
@@ -457,9 +458,9 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:   %b.ref: f64 = name_ref b, %b
 // CHECK:STDOUT:   %c.ref: f64 = name_ref c, %c
 // CHECK:STDOUT:   %TooMany.call: init f64 = call %TooMany.ref(%a.ref, %b.ref, %c.ref)
-// CHECK:STDOUT:   %.loc25_26.1: f64 = value_of_initializer %TooMany.call
-// CHECK:STDOUT:   %.loc25_26.2: f64 = converted %TooMany.call, %.loc25_26.1
-// CHECK:STDOUT:   return %.loc25_26.2
+// CHECK:STDOUT:   %.loc26_26.1: f64 = value_of_initializer %TooMany.call
+// CHECK:STDOUT:   %.loc26_26.2: f64 = converted %TooMany.call, %.loc26_26.1
+// CHECK:STDOUT:   return %.loc26_26.2
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @RuntimeCallIsValidBadReturnType(%a.param_patt: f64, %b.param_patt: f64) -> bool {
@@ -468,8 +469,8 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:   %a.ref: f64 = name_ref a, %a
 // CHECK:STDOUT:   %b.ref: f64 = name_ref b, %b
 // CHECK:STDOUT:   %BadReturnType.call: init bool = call %BadReturnType.ref(%a.ref, %b.ref)
-// CHECK:STDOUT:   %.loc29_29.1: bool = value_of_initializer %BadReturnType.call
-// CHECK:STDOUT:   %.loc29_29.2: bool = converted %BadReturnType.call, %.loc29_29.1
-// CHECK:STDOUT:   return %.loc29_29.2
+// CHECK:STDOUT:   %.loc30_29.1: bool = value_of_initializer %BadReturnType.call
+// CHECK:STDOUT:   %.loc30_29.2: bool = converted %BadReturnType.call, %.loc30_29.1
+// CHECK:STDOUT:   return %.loc30_29.2
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/builtins/float/div.carbon b/toolchain/check/testdata/builtins/float/div.carbon
index a4656f8ad9e3..1b0efeb68d2e 100644
--- a/toolchain/check/testdata/builtins/float/div.carbon
+++ b/toolchain/check/testdata/builtins/float/div.carbon
@@ -34,9 +34,10 @@ fn TooFew(a: f64) -> f64 = "float.div";
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
 fn TooMany(a: f64, b: f64, c: f64) -> f64 = "float.div";
-// CHECK:STDERR: fail_bad_decl.carbon:[[@LINE+3]]:1: error: invalid signature for builtin function "float.div" [InvalidBuiltinSignature]
+// CHECK:STDERR: fail_bad_decl.carbon:[[@LINE+4]]:1: error: invalid signature for builtin function "float.div" [InvalidBuiltinSignature]
 // CHECK:STDERR: fn BadReturnType(a: f64, b: f64) -> bool = "float.div";
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 fn BadReturnType(a: f64, b: f64) -> bool = "float.div";
 fn JustRight(a: f64, b: f64) -> f64 = "float.div";
 
@@ -308,22 +309,22 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:     %return.param_patt: bool = out_param_pattern %return.patt, runtime_param2
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %bool.make_type: init type = call constants.%Bool() [template = bool]
-// CHECK:STDOUT:     %.loc17_37.1: type = value_of_initializer %bool.make_type [template = bool]
-// CHECK:STDOUT:     %.loc17_37.2: type = converted %bool.make_type, %.loc17_37.1 [template = bool]
+// CHECK:STDOUT:     %.loc18_37.1: type = value_of_initializer %bool.make_type [template = bool]
+// CHECK:STDOUT:     %.loc18_37.2: type = converted %bool.make_type, %.loc18_37.1 [template = bool]
 // CHECK:STDOUT:     %a.param: f64 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc17_21.1: type = splice_block %.loc17_21.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc17_21: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc17_21: init type = call constants.%Float(%int_64.loc17_21) [template = f64]
-// CHECK:STDOUT:       %.loc17_21.2: type = value_of_initializer %float.make_type.loc17_21 [template = f64]
-// CHECK:STDOUT:       %.loc17_21.3: type = converted %float.make_type.loc17_21, %.loc17_21.2 [template = f64]
+// CHECK:STDOUT:     %.loc18_21.1: type = splice_block %.loc18_21.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc18_21: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc18_21: init type = call constants.%Float(%int_64.loc18_21) [template = f64]
+// CHECK:STDOUT:       %.loc18_21.2: type = value_of_initializer %float.make_type.loc18_21 [template = f64]
+// CHECK:STDOUT:       %.loc18_21.3: type = converted %float.make_type.loc18_21, %.loc18_21.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: f64 = bind_name a, %a.param
 // CHECK:STDOUT:     %b.param: f64 = value_param runtime_param1
-// CHECK:STDOUT:     %.loc17_29.1: type = splice_block %.loc17_29.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc17_29: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc17_29: init type = call constants.%Float(%int_64.loc17_29) [template = f64]
-// CHECK:STDOUT:       %.loc17_29.2: type = value_of_initializer %float.make_type.loc17_29 [template = f64]
-// CHECK:STDOUT:       %.loc17_29.3: type = converted %float.make_type.loc17_29, %.loc17_29.2 [template = f64]
+// CHECK:STDOUT:     %.loc18_29.1: type = splice_block %.loc18_29.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc18_29: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc18_29: init type = call constants.%Float(%int_64.loc18_29) [template = f64]
+// CHECK:STDOUT:       %.loc18_29.2: type = value_of_initializer %float.make_type.loc18_29 [template = f64]
+// CHECK:STDOUT:       %.loc18_29.3: type = converted %float.make_type.loc18_29, %.loc18_29.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %b: f64 = bind_name b, %b.param
 // CHECK:STDOUT:     %return.param: ref bool = out_param runtime_param2
@@ -337,24 +338,24 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:     %return.patt: f64 = return_slot_pattern
 // CHECK:STDOUT:     %return.param_patt: f64 = out_param_pattern %return.patt, runtime_param2
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %int_64.loc18_33: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:     %float.make_type.loc18_33: init type = call constants.%Float(%int_64.loc18_33) [template = f64]
-// CHECK:STDOUT:     %.loc18_33.1: type = value_of_initializer %float.make_type.loc18_33 [template = f64]
-// CHECK:STDOUT:     %.loc18_33.2: type = converted %float.make_type.loc18_33, %.loc18_33.1 [template = f64]
+// CHECK:STDOUT:     %int_64.loc19_33: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:     %float.make_type.loc19_33: init type = call constants.%Float(%int_64.loc19_33) [template = f64]
+// CHECK:STDOUT:     %.loc19_33.1: type = value_of_initializer %float.make_type.loc19_33 [template = f64]
+// CHECK:STDOUT:     %.loc19_33.2: type = converted %float.make_type.loc19_33, %.loc19_33.1 [template = f64]
 // CHECK:STDOUT:     %a.param: f64 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc18_17.1: type = splice_block %.loc18_17.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc18_17: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc18_17: init type = call constants.%Float(%int_64.loc18_17) [template = f64]
-// CHECK:STDOUT:       %.loc18_17.2: type = value_of_initializer %float.make_type.loc18_17 [template = f64]
-// CHECK:STDOUT:       %.loc18_17.3: type = converted %float.make_type.loc18_17, %.loc18_17.2 [template = f64]
+// CHECK:STDOUT:     %.loc19_17.1: type = splice_block %.loc19_17.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc19_17: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc19_17: init type = call constants.%Float(%int_64.loc19_17) [template = f64]
+// CHECK:STDOUT:       %.loc19_17.2: type = value_of_initializer %float.make_type.loc19_17 [template = f64]
+// CHECK:STDOUT:       %.loc19_17.3: type = converted %float.make_type.loc19_17, %.loc19_17.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: f64 = bind_name a, %a.param
 // CHECK:STDOUT:     %b.param: f64 = value_param runtime_param1
-// CHECK:STDOUT:     %.loc18_25.1: type = splice_block %.loc18_25.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc18_25: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc18_25: init type = call constants.%Float(%int_64.loc18_25) [template = f64]
-// CHECK:STDOUT:       %.loc18_25.2: type = value_of_initializer %float.make_type.loc18_25 [template = f64]
-// CHECK:STDOUT:       %.loc18_25.3: type = converted %float.make_type.loc18_25, %.loc18_25.2 [template = f64]
+// CHECK:STDOUT:     %.loc19_25.1: type = splice_block %.loc19_25.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc19_25: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc19_25: init type = call constants.%Float(%int_64.loc19_25) [template = f64]
+// CHECK:STDOUT:       %.loc19_25.2: type = value_of_initializer %float.make_type.loc19_25 [template = f64]
+// CHECK:STDOUT:       %.loc19_25.3: type = converted %float.make_type.loc19_25, %.loc19_25.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %b: f64 = bind_name b, %b.param
 // CHECK:STDOUT:     %return.param: ref f64 = out_param runtime_param2
@@ -366,16 +367,16 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:     %return.patt: f64 = return_slot_pattern
 // CHECK:STDOUT:     %return.param_patt: f64 = out_param_pattern %return.patt, runtime_param1
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %int_64.loc20_40: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:     %float.make_type.loc20_40: init type = call constants.%Float(%int_64.loc20_40) [template = f64]
-// CHECK:STDOUT:     %.loc20_40.1: type = value_of_initializer %float.make_type.loc20_40 [template = f64]
-// CHECK:STDOUT:     %.loc20_40.2: type = converted %float.make_type.loc20_40, %.loc20_40.1 [template = f64]
+// CHECK:STDOUT:     %int_64.loc21_40: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:     %float.make_type.loc21_40: init type = call constants.%Float(%int_64.loc21_40) [template = f64]
+// CHECK:STDOUT:     %.loc21_40.1: type = value_of_initializer %float.make_type.loc21_40 [template = f64]
+// CHECK:STDOUT:     %.loc21_40.2: type = converted %float.make_type.loc21_40, %.loc21_40.1 [template = f64]
 // CHECK:STDOUT:     %a.param: f64 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc20_32.1: type = splice_block %.loc20_32.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc20_32: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc20_32: init type = call constants.%Float(%int_64.loc20_32) [template = f64]
-// CHECK:STDOUT:       %.loc20_32.2: type = value_of_initializer %float.make_type.loc20_32 [template = f64]
-// CHECK:STDOUT:       %.loc20_32.3: type = converted %float.make_type.loc20_32, %.loc20_32.2 [template = f64]
+// CHECK:STDOUT:     %.loc21_32.1: type = splice_block %.loc21_32.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc21_32: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc21_32: init type = call constants.%Float(%int_64.loc21_32) [template = f64]
+// CHECK:STDOUT:       %.loc21_32.2: type = value_of_initializer %float.make_type.loc21_32 [template = f64]
+// CHECK:STDOUT:       %.loc21_32.3: type = converted %float.make_type.loc21_32, %.loc21_32.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: f64 = bind_name a, %a.param
 // CHECK:STDOUT:     %return.param: ref f64 = out_param runtime_param1
@@ -391,32 +392,32 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:     %return.patt: f64 = return_slot_pattern
 // CHECK:STDOUT:     %return.param_patt: f64 = out_param_pattern %return.patt, runtime_param3
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %int_64.loc24_57: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:     %float.make_type.loc24_57: init type = call constants.%Float(%int_64.loc24_57) [template = f64]
-// CHECK:STDOUT:     %.loc24_57.1: type = value_of_initializer %float.make_type.loc24_57 [template = f64]
-// CHECK:STDOUT:     %.loc24_57.2: type = converted %float.make_type.loc24_57, %.loc24_57.1 [template = f64]
+// CHECK:STDOUT:     %int_64.loc25_57: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:     %float.make_type.loc25_57: init type = call constants.%Float(%int_64.loc25_57) [template = f64]
+// CHECK:STDOUT:     %.loc25_57.1: type = value_of_initializer %float.make_type.loc25_57 [template = f64]
+// CHECK:STDOUT:     %.loc25_57.2: type = converted %float.make_type.loc25_57, %.loc25_57.1 [template = f64]
 // CHECK:STDOUT:     %a.param: f64 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc24_33.1: type = splice_block %.loc24_33.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc24_33: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc24_33: init type = call constants.%Float(%int_64.loc24_33) [template = f64]
-// CHECK:STDOUT:       %.loc24_33.2: type = value_of_initializer %float.make_type.loc24_33 [template = f64]
-// CHECK:STDOUT:       %.loc24_33.3: type = converted %float.make_type.loc24_33, %.loc24_33.2 [template = f64]
+// CHECK:STDOUT:     %.loc25_33.1: type = splice_block %.loc25_33.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc25_33: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc25_33: init type = call constants.%Float(%int_64.loc25_33) [template = f64]
+// CHECK:STDOUT:       %.loc25_33.2: type = value_of_initializer %float.make_type.loc25_33 [template = f64]
+// CHECK:STDOUT:       %.loc25_33.3: type = converted %float.make_type.loc25_33, %.loc25_33.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: f64 = bind_name a, %a.param
 // CHECK:STDOUT:     %b.param: f64 = value_param runtime_param1
-// CHECK:STDOUT:     %.loc24_41.1: type = splice_block %.loc24_41.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc24_41: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc24_41: init type = call constants.%Float(%int_64.loc24_41) [template = f64]
-// CHECK:STDOUT:       %.loc24_41.2: type = value_of_initializer %float.make_type.loc24_41 [template = f64]
-// CHECK:STDOUT:       %.loc24_41.3: type = converted %float.make_type.loc24_41, %.loc24_41.2 [template = f64]
+// CHECK:STDOUT:     %.loc25_41.1: type = splice_block %.loc25_41.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc25_41: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc25_41: init type = call constants.%Float(%int_64.loc25_41) [template = f64]
+// CHECK:STDOUT:       %.loc25_41.2: type = value_of_initializer %float.make_type.loc25_41 [template = f64]
+// CHECK:STDOUT:       %.loc25_41.3: type = converted %float.make_type.loc25_41, %.loc25_41.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %b: f64 = bind_name b, %b.param
 // CHECK:STDOUT:     %c.param: f64 = value_param runtime_param2
-// CHECK:STDOUT:     %.loc24_49.1: type = splice_block %.loc24_49.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc24_49: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc24_49: init type = call constants.%Float(%int_64.loc24_49) [template = f64]
-// CHECK:STDOUT:       %.loc24_49.2: type = value_of_initializer %float.make_type.loc24_49 [template = f64]
-// CHECK:STDOUT:       %.loc24_49.3: type = converted %float.make_type.loc24_49, %.loc24_49.2 [template = f64]
+// CHECK:STDOUT:     %.loc25_49.1: type = splice_block %.loc25_49.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc25_49: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc25_49: init type = call constants.%Float(%int_64.loc25_49) [template = f64]
+// CHECK:STDOUT:       %.loc25_49.2: type = value_of_initializer %float.make_type.loc25_49 [template = f64]
+// CHECK:STDOUT:       %.loc25_49.3: type = converted %float.make_type.loc25_49, %.loc25_49.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %c: f64 = bind_name c, %c.param
 // CHECK:STDOUT:     %return.param: ref f64 = out_param runtime_param3
@@ -431,22 +432,22 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:     %return.param_patt: bool = out_param_pattern %return.patt, runtime_param2
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %bool.make_type: init type = call constants.%Bool() [template = bool]
-// CHECK:STDOUT:     %.loc28_55.1: type = value_of_initializer %bool.make_type [template = bool]
-// CHECK:STDOUT:     %.loc28_55.2: type = converted %bool.make_type, %.loc28_55.1 [template = bool]
+// CHECK:STDOUT:     %.loc29_55.1: type = value_of_initializer %bool.make_type [template = bool]
+// CHECK:STDOUT:     %.loc29_55.2: type = converted %bool.make_type, %.loc29_55.1 [template = bool]
 // CHECK:STDOUT:     %a.param: f64 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc28_39.1: type = splice_block %.loc28_39.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc28_39: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc28_39: init type = call constants.%Float(%int_64.loc28_39) [template = f64]
-// CHECK:STDOUT:       %.loc28_39.2: type = value_of_initializer %float.make_type.loc28_39 [template = f64]
-// CHECK:STDOUT:       %.loc28_39.3: type = converted %float.make_type.loc28_39, %.loc28_39.2 [template = f64]
+// CHECK:STDOUT:     %.loc29_39.1: type = splice_block %.loc29_39.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc29_39: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc29_39: init type = call constants.%Float(%int_64.loc29_39) [template = f64]
+// CHECK:STDOUT:       %.loc29_39.2: type = value_of_initializer %float.make_type.loc29_39 [template = f64]
+// CHECK:STDOUT:       %.loc29_39.3: type = converted %float.make_type.loc29_39, %.loc29_39.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: f64 = bind_name a, %a.param
 // CHECK:STDOUT:     %b.param: f64 = value_param runtime_param1
-// CHECK:STDOUT:     %.loc28_47.1: type = splice_block %.loc28_47.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc28_47: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc28_47: init type = call constants.%Float(%int_64.loc28_47) [template = f64]
-// CHECK:STDOUT:       %.loc28_47.2: type = value_of_initializer %float.make_type.loc28_47 [template = f64]
-// CHECK:STDOUT:       %.loc28_47.3: type = converted %float.make_type.loc28_47, %.loc28_47.2 [template = f64]
+// CHECK:STDOUT:     %.loc29_47.1: type = splice_block %.loc29_47.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc29_47: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc29_47: init type = call constants.%Float(%int_64.loc29_47) [template = f64]
+// CHECK:STDOUT:       %.loc29_47.2: type = value_of_initializer %float.make_type.loc29_47 [template = f64]
+// CHECK:STDOUT:       %.loc29_47.3: type = converted %float.make_type.loc29_47, %.loc29_47.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %b: f64 = bind_name b, %b.param
 // CHECK:STDOUT:     %return.param: ref bool = out_param runtime_param2
@@ -467,9 +468,9 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:   %TooFew.ref: %TooFew.type = name_ref TooFew, file.%TooFew.decl [template = constants.%TooFew]
 // CHECK:STDOUT:   %a.ref: f64 = name_ref a, %a
 // CHECK:STDOUT:   %TooFew.call: init f64 = call %TooFew.ref(%a.ref)
-// CHECK:STDOUT:   %.loc21_19.1: f64 = value_of_initializer %TooFew.call
-// CHECK:STDOUT:   %.loc21_19.2: f64 = converted %TooFew.call, %.loc21_19.1
-// CHECK:STDOUT:   return %.loc21_19.2
+// CHECK:STDOUT:   %.loc22_19.1: f64 = value_of_initializer %TooFew.call
+// CHECK:STDOUT:   %.loc22_19.2: f64 = converted %TooFew.call, %.loc22_19.1
+// CHECK:STDOUT:   return %.loc22_19.2
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @RuntimeCallIsValidTooMany(%a.param_patt: f64, %b.param_patt: f64, %c.param_patt: f64) -> f64 {
@@ -479,9 +480,9 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:   %b.ref: f64 = name_ref b, %b
 // CHECK:STDOUT:   %c.ref: f64 = name_ref c, %c
 // CHECK:STDOUT:   %TooMany.call: init f64 = call %TooMany.ref(%a.ref, %b.ref, %c.ref)
-// CHECK:STDOUT:   %.loc25_26.1: f64 = value_of_initializer %TooMany.call
-// CHECK:STDOUT:   %.loc25_26.2: f64 = converted %TooMany.call, %.loc25_26.1
-// CHECK:STDOUT:   return %.loc25_26.2
+// CHECK:STDOUT:   %.loc26_26.1: f64 = value_of_initializer %TooMany.call
+// CHECK:STDOUT:   %.loc26_26.2: f64 = converted %TooMany.call, %.loc26_26.1
+// CHECK:STDOUT:   return %.loc26_26.2
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @RuntimeCallIsValidBadReturnType(%a.param_patt: f64, %b.param_patt: f64) -> bool {
@@ -490,8 +491,8 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:   %a.ref: f64 = name_ref a, %a
 // CHECK:STDOUT:   %b.ref: f64 = name_ref b, %b
 // CHECK:STDOUT:   %BadReturnType.call: init bool = call %BadReturnType.ref(%a.ref, %b.ref)
-// CHECK:STDOUT:   %.loc29_29.1: bool = value_of_initializer %BadReturnType.call
-// CHECK:STDOUT:   %.loc29_29.2: bool = converted %BadReturnType.call, %.loc29_29.1
-// CHECK:STDOUT:   return %.loc29_29.2
+// CHECK:STDOUT:   %.loc30_29.1: bool = value_of_initializer %BadReturnType.call
+// CHECK:STDOUT:   %.loc30_29.2: bool = converted %BadReturnType.call, %.loc30_29.1
+// CHECK:STDOUT:   return %.loc30_29.2
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/builtins/float/eq.carbon b/toolchain/check/testdata/builtins/float/eq.carbon
index 1b4ffa527503..cd35b3bc03db 100644
--- a/toolchain/check/testdata/builtins/float/eq.carbon
+++ b/toolchain/check/testdata/builtins/float/eq.carbon
@@ -28,9 +28,10 @@ fn RuntimeCallIsValid(a: f64, b: f64) -> bool {
 
 package FailBadDecl;
 
-// CHECK:STDERR: fail_bad_decl.carbon:[[@LINE+3]]:1: error: invalid signature for builtin function "float.eq" [InvalidBuiltinSignature]
+// CHECK:STDERR: fail_bad_decl.carbon:[[@LINE+4]]:1: error: invalid signature for builtin function "float.eq" [InvalidBuiltinSignature]
 // CHECK:STDERR: fn WrongResult(a: f64, b: f64) -> f64 = "float.eq";
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 fn WrongResult(a: f64, b: f64) -> f64 = "float.eq";
 
 // CHECK:STDOUT: --- float_eq.carbon
@@ -251,24 +252,24 @@ fn WrongResult(a: f64, b: f64) -> f64 = "float.eq";
 // CHECK:STDOUT:     %return.patt: f64 = return_slot_pattern
 // CHECK:STDOUT:     %return.param_patt: f64 = out_param_pattern %return.patt, runtime_param2
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %int_64.loc7_35: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:     %float.make_type.loc7_35: init type = call constants.%Float(%int_64.loc7_35) [template = f64]
-// CHECK:STDOUT:     %.loc7_35.1: type = value_of_initializer %float.make_type.loc7_35 [template = f64]
-// CHECK:STDOUT:     %.loc7_35.2: type = converted %float.make_type.loc7_35, %.loc7_35.1 [template = f64]
+// CHECK:STDOUT:     %int_64.loc8_35: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:     %float.make_type.loc8_35: init type = call constants.%Float(%int_64.loc8_35) [template = f64]
+// CHECK:STDOUT:     %.loc8_35.1: type = value_of_initializer %float.make_type.loc8_35 [template = f64]
+// CHECK:STDOUT:     %.loc8_35.2: type = converted %float.make_type.loc8_35, %.loc8_35.1 [template = f64]
 // CHECK:STDOUT:     %a.param: f64 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc7_19.1: type = splice_block %.loc7_19.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc7_19: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc7_19: init type = call constants.%Float(%int_64.loc7_19) [template = f64]
-// CHECK:STDOUT:       %.loc7_19.2: type = value_of_initializer %float.make_type.loc7_19 [template = f64]
-// CHECK:STDOUT:       %.loc7_19.3: type = converted %float.make_type.loc7_19, %.loc7_19.2 [template = f64]
+// CHECK:STDOUT:     %.loc8_19.1: type = splice_block %.loc8_19.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc8_19: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc8_19: init type = call constants.%Float(%int_64.loc8_19) [template = f64]
+// CHECK:STDOUT:       %.loc8_19.2: type = value_of_initializer %float.make_type.loc8_19 [template = f64]
+// CHECK:STDOUT:       %.loc8_19.3: type = converted %float.make_type.loc8_19, %.loc8_19.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: f64 = bind_name a, %a.param
 // CHECK:STDOUT:     %b.param: f64 = value_param runtime_param1
-// CHECK:STDOUT:     %.loc7_27.1: type = splice_block %.loc7_27.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc7_27: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc7_27: init type = call constants.%Float(%int_64.loc7_27) [template = f64]
-// CHECK:STDOUT:       %.loc7_27.2: type = value_of_initializer %float.make_type.loc7_27 [template = f64]
-// CHECK:STDOUT:       %.loc7_27.3: type = converted %float.make_type.loc7_27, %.loc7_27.2 [template = f64]
+// CHECK:STDOUT:     %.loc8_27.1: type = splice_block %.loc8_27.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc8_27: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc8_27: init type = call constants.%Float(%int_64.loc8_27) [template = f64]
+// CHECK:STDOUT:       %.loc8_27.2: type = value_of_initializer %float.make_type.loc8_27 [template = f64]
+// CHECK:STDOUT:       %.loc8_27.3: type = converted %float.make_type.loc8_27, %.loc8_27.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %b: f64 = bind_name b, %b.param
 // CHECK:STDOUT:     %return.param: ref f64 = out_param runtime_param2
diff --git a/toolchain/check/testdata/builtins/float/make_type.carbon b/toolchain/check/testdata/builtins/float/make_type.carbon
index 13d026d82539..29bdd34a6db6 100644
--- a/toolchain/check/testdata/builtins/float/make_type.carbon
+++ b/toolchain/check/testdata/builtins/float/make_type.carbon
@@ -39,9 +39,10 @@ import library "types";
 var invalid_float: Float(32);
 
 var dyn_size: i32 = 64;
-// CHECK:STDERR: fail_invalid_size.carbon:[[@LINE+3]]:10: error: cannot evaluate type expression [TypeExprEvaluationFailure]
+// CHECK:STDERR: fail_invalid_size.carbon:[[@LINE+4]]:10: error: cannot evaluate type expression [TypeExprEvaluationFailure]
 // CHECK:STDERR: var dyn: Float(dyn_size);
 // CHECK:STDERR:          ^~~~~~~~~~~~~~~
+// CHECK:STDERR:
 var dyn: Float(dyn_size);
 
 // CHECK:STDOUT: --- types.carbon
diff --git a/toolchain/check/testdata/builtins/float/mul.carbon b/toolchain/check/testdata/builtins/float/mul.carbon
index ac1c6df53f0d..1b91402214b8 100644
--- a/toolchain/check/testdata/builtins/float/mul.carbon
+++ b/toolchain/check/testdata/builtins/float/mul.carbon
@@ -32,9 +32,10 @@ fn TooFew(a: f64) -> f64 = "float.mul";
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
 fn TooMany(a: f64, b: f64, c: f64) -> f64 = "float.mul";
-// CHECK:STDERR: fail_bad_decl.carbon:[[@LINE+3]]:1: error: invalid signature for builtin function "float.mul" [InvalidBuiltinSignature]
+// CHECK:STDERR: fail_bad_decl.carbon:[[@LINE+4]]:1: error: invalid signature for builtin function "float.mul" [InvalidBuiltinSignature]
 // CHECK:STDERR: fn BadReturnType(a: f64, b: f64) -> bool = "float.mul";
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 fn BadReturnType(a: f64, b: f64) -> bool = "float.mul";
 fn JustRight(a: f64, b: f64) -> f64 = "float.mul";
 
@@ -286,22 +287,22 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:     %return.param_patt: bool = out_param_pattern %return.patt, runtime_param2
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %bool.make_type: init type = call constants.%Bool() [template = bool]
-// CHECK:STDOUT:     %.loc17_37.1: type = value_of_initializer %bool.make_type [template = bool]
-// CHECK:STDOUT:     %.loc17_37.2: type = converted %bool.make_type, %.loc17_37.1 [template = bool]
+// CHECK:STDOUT:     %.loc18_37.1: type = value_of_initializer %bool.make_type [template = bool]
+// CHECK:STDOUT:     %.loc18_37.2: type = converted %bool.make_type, %.loc18_37.1 [template = bool]
 // CHECK:STDOUT:     %a.param: f64 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc17_21.1: type = splice_block %.loc17_21.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc17_21: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc17_21: init type = call constants.%Float(%int_64.loc17_21) [template = f64]
-// CHECK:STDOUT:       %.loc17_21.2: type = value_of_initializer %float.make_type.loc17_21 [template = f64]
-// CHECK:STDOUT:       %.loc17_21.3: type = converted %float.make_type.loc17_21, %.loc17_21.2 [template = f64]
+// CHECK:STDOUT:     %.loc18_21.1: type = splice_block %.loc18_21.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc18_21: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc18_21: init type = call constants.%Float(%int_64.loc18_21) [template = f64]
+// CHECK:STDOUT:       %.loc18_21.2: type = value_of_initializer %float.make_type.loc18_21 [template = f64]
+// CHECK:STDOUT:       %.loc18_21.3: type = converted %float.make_type.loc18_21, %.loc18_21.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: f64 = bind_name a, %a.param
 // CHECK:STDOUT:     %b.param: f64 = value_param runtime_param1
-// CHECK:STDOUT:     %.loc17_29.1: type = splice_block %.loc17_29.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc17_29: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc17_29: init type = call constants.%Float(%int_64.loc17_29) [template = f64]
-// CHECK:STDOUT:       %.loc17_29.2: type = value_of_initializer %float.make_type.loc17_29 [template = f64]
-// CHECK:STDOUT:       %.loc17_29.3: type = converted %float.make_type.loc17_29, %.loc17_29.2 [template = f64]
+// CHECK:STDOUT:     %.loc18_29.1: type = splice_block %.loc18_29.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc18_29: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc18_29: init type = call constants.%Float(%int_64.loc18_29) [template = f64]
+// CHECK:STDOUT:       %.loc18_29.2: type = value_of_initializer %float.make_type.loc18_29 [template = f64]
+// CHECK:STDOUT:       %.loc18_29.3: type = converted %float.make_type.loc18_29, %.loc18_29.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %b: f64 = bind_name b, %b.param
 // CHECK:STDOUT:     %return.param: ref bool = out_param runtime_param2
@@ -315,24 +316,24 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:     %return.patt: f64 = return_slot_pattern
 // CHECK:STDOUT:     %return.param_patt: f64 = out_param_pattern %return.patt, runtime_param2
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %int_64.loc18_33: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:     %float.make_type.loc18_33: init type = call constants.%Float(%int_64.loc18_33) [template = f64]
-// CHECK:STDOUT:     %.loc18_33.1: type = value_of_initializer %float.make_type.loc18_33 [template = f64]
-// CHECK:STDOUT:     %.loc18_33.2: type = converted %float.make_type.loc18_33, %.loc18_33.1 [template = f64]
+// CHECK:STDOUT:     %int_64.loc19_33: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:     %float.make_type.loc19_33: init type = call constants.%Float(%int_64.loc19_33) [template = f64]
+// CHECK:STDOUT:     %.loc19_33.1: type = value_of_initializer %float.make_type.loc19_33 [template = f64]
+// CHECK:STDOUT:     %.loc19_33.2: type = converted %float.make_type.loc19_33, %.loc19_33.1 [template = f64]
 // CHECK:STDOUT:     %a.param: f64 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc18_17.1: type = splice_block %.loc18_17.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc18_17: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc18_17: init type = call constants.%Float(%int_64.loc18_17) [template = f64]
-// CHECK:STDOUT:       %.loc18_17.2: type = value_of_initializer %float.make_type.loc18_17 [template = f64]
-// CHECK:STDOUT:       %.loc18_17.3: type = converted %float.make_type.loc18_17, %.loc18_17.2 [template = f64]
+// CHECK:STDOUT:     %.loc19_17.1: type = splice_block %.loc19_17.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc19_17: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc19_17: init type = call constants.%Float(%int_64.loc19_17) [template = f64]
+// CHECK:STDOUT:       %.loc19_17.2: type = value_of_initializer %float.make_type.loc19_17 [template = f64]
+// CHECK:STDOUT:       %.loc19_17.3: type = converted %float.make_type.loc19_17, %.loc19_17.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: f64 = bind_name a, %a.param
 // CHECK:STDOUT:     %b.param: f64 = value_param runtime_param1
-// CHECK:STDOUT:     %.loc18_25.1: type = splice_block %.loc18_25.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc18_25: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc18_25: init type = call constants.%Float(%int_64.loc18_25) [template = f64]
-// CHECK:STDOUT:       %.loc18_25.2: type = value_of_initializer %float.make_type.loc18_25 [template = f64]
-// CHECK:STDOUT:       %.loc18_25.3: type = converted %float.make_type.loc18_25, %.loc18_25.2 [template = f64]
+// CHECK:STDOUT:     %.loc19_25.1: type = splice_block %.loc19_25.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc19_25: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc19_25: init type = call constants.%Float(%int_64.loc19_25) [template = f64]
+// CHECK:STDOUT:       %.loc19_25.2: type = value_of_initializer %float.make_type.loc19_25 [template = f64]
+// CHECK:STDOUT:       %.loc19_25.3: type = converted %float.make_type.loc19_25, %.loc19_25.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %b: f64 = bind_name b, %b.param
 // CHECK:STDOUT:     %return.param: ref f64 = out_param runtime_param2
@@ -344,16 +345,16 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:     %return.patt: f64 = return_slot_pattern
 // CHECK:STDOUT:     %return.param_patt: f64 = out_param_pattern %return.patt, runtime_param1
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %int_64.loc20_40: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:     %float.make_type.loc20_40: init type = call constants.%Float(%int_64.loc20_40) [template = f64]
-// CHECK:STDOUT:     %.loc20_40.1: type = value_of_initializer %float.make_type.loc20_40 [template = f64]
-// CHECK:STDOUT:     %.loc20_40.2: type = converted %float.make_type.loc20_40, %.loc20_40.1 [template = f64]
+// CHECK:STDOUT:     %int_64.loc21_40: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:     %float.make_type.loc21_40: init type = call constants.%Float(%int_64.loc21_40) [template = f64]
+// CHECK:STDOUT:     %.loc21_40.1: type = value_of_initializer %float.make_type.loc21_40 [template = f64]
+// CHECK:STDOUT:     %.loc21_40.2: type = converted %float.make_type.loc21_40, %.loc21_40.1 [template = f64]
 // CHECK:STDOUT:     %a.param: f64 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc20_32.1: type = splice_block %.loc20_32.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc20_32: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc20_32: init type = call constants.%Float(%int_64.loc20_32) [template = f64]
-// CHECK:STDOUT:       %.loc20_32.2: type = value_of_initializer %float.make_type.loc20_32 [template = f64]
-// CHECK:STDOUT:       %.loc20_32.3: type = converted %float.make_type.loc20_32, %.loc20_32.2 [template = f64]
+// CHECK:STDOUT:     %.loc21_32.1: type = splice_block %.loc21_32.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc21_32: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc21_32: init type = call constants.%Float(%int_64.loc21_32) [template = f64]
+// CHECK:STDOUT:       %.loc21_32.2: type = value_of_initializer %float.make_type.loc21_32 [template = f64]
+// CHECK:STDOUT:       %.loc21_32.3: type = converted %float.make_type.loc21_32, %.loc21_32.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: f64 = bind_name a, %a.param
 // CHECK:STDOUT:     %return.param: ref f64 = out_param runtime_param1
@@ -369,32 +370,32 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:     %return.patt: f64 = return_slot_pattern
 // CHECK:STDOUT:     %return.param_patt: f64 = out_param_pattern %return.patt, runtime_param3
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %int_64.loc24_57: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:     %float.make_type.loc24_57: init type = call constants.%Float(%int_64.loc24_57) [template = f64]
-// CHECK:STDOUT:     %.loc24_57.1: type = value_of_initializer %float.make_type.loc24_57 [template = f64]
-// CHECK:STDOUT:     %.loc24_57.2: type = converted %float.make_type.loc24_57, %.loc24_57.1 [template = f64]
+// CHECK:STDOUT:     %int_64.loc25_57: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:     %float.make_type.loc25_57: init type = call constants.%Float(%int_64.loc25_57) [template = f64]
+// CHECK:STDOUT:     %.loc25_57.1: type = value_of_initializer %float.make_type.loc25_57 [template = f64]
+// CHECK:STDOUT:     %.loc25_57.2: type = converted %float.make_type.loc25_57, %.loc25_57.1 [template = f64]
 // CHECK:STDOUT:     %a.param: f64 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc24_33.1: type = splice_block %.loc24_33.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc24_33: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc24_33: init type = call constants.%Float(%int_64.loc24_33) [template = f64]
-// CHECK:STDOUT:       %.loc24_33.2: type = value_of_initializer %float.make_type.loc24_33 [template = f64]
-// CHECK:STDOUT:       %.loc24_33.3: type = converted %float.make_type.loc24_33, %.loc24_33.2 [template = f64]
+// CHECK:STDOUT:     %.loc25_33.1: type = splice_block %.loc25_33.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc25_33: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc25_33: init type = call constants.%Float(%int_64.loc25_33) [template = f64]
+// CHECK:STDOUT:       %.loc25_33.2: type = value_of_initializer %float.make_type.loc25_33 [template = f64]
+// CHECK:STDOUT:       %.loc25_33.3: type = converted %float.make_type.loc25_33, %.loc25_33.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: f64 = bind_name a, %a.param
 // CHECK:STDOUT:     %b.param: f64 = value_param runtime_param1
-// CHECK:STDOUT:     %.loc24_41.1: type = splice_block %.loc24_41.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc24_41: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc24_41: init type = call constants.%Float(%int_64.loc24_41) [template = f64]
-// CHECK:STDOUT:       %.loc24_41.2: type = value_of_initializer %float.make_type.loc24_41 [template = f64]
-// CHECK:STDOUT:       %.loc24_41.3: type = converted %float.make_type.loc24_41, %.loc24_41.2 [template = f64]
+// CHECK:STDOUT:     %.loc25_41.1: type = splice_block %.loc25_41.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc25_41: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc25_41: init type = call constants.%Float(%int_64.loc25_41) [template = f64]
+// CHECK:STDOUT:       %.loc25_41.2: type = value_of_initializer %float.make_type.loc25_41 [template = f64]
+// CHECK:STDOUT:       %.loc25_41.3: type = converted %float.make_type.loc25_41, %.loc25_41.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %b: f64 = bind_name b, %b.param
 // CHECK:STDOUT:     %c.param: f64 = value_param runtime_param2
-// CHECK:STDOUT:     %.loc24_49.1: type = splice_block %.loc24_49.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc24_49: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc24_49: init type = call constants.%Float(%int_64.loc24_49) [template = f64]
-// CHECK:STDOUT:       %.loc24_49.2: type = value_of_initializer %float.make_type.loc24_49 [template = f64]
-// CHECK:STDOUT:       %.loc24_49.3: type = converted %float.make_type.loc24_49, %.loc24_49.2 [template = f64]
+// CHECK:STDOUT:     %.loc25_49.1: type = splice_block %.loc25_49.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc25_49: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc25_49: init type = call constants.%Float(%int_64.loc25_49) [template = f64]
+// CHECK:STDOUT:       %.loc25_49.2: type = value_of_initializer %float.make_type.loc25_49 [template = f64]
+// CHECK:STDOUT:       %.loc25_49.3: type = converted %float.make_type.loc25_49, %.loc25_49.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %c: f64 = bind_name c, %c.param
 // CHECK:STDOUT:     %return.param: ref f64 = out_param runtime_param3
@@ -409,22 +410,22 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:     %return.param_patt: bool = out_param_pattern %return.patt, runtime_param2
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %bool.make_type: init type = call constants.%Bool() [template = bool]
-// CHECK:STDOUT:     %.loc28_55.1: type = value_of_initializer %bool.make_type [template = bool]
-// CHECK:STDOUT:     %.loc28_55.2: type = converted %bool.make_type, %.loc28_55.1 [template = bool]
+// CHECK:STDOUT:     %.loc29_55.1: type = value_of_initializer %bool.make_type [template = bool]
+// CHECK:STDOUT:     %.loc29_55.2: type = converted %bool.make_type, %.loc29_55.1 [template = bool]
 // CHECK:STDOUT:     %a.param: f64 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc28_39.1: type = splice_block %.loc28_39.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc28_39: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc28_39: init type = call constants.%Float(%int_64.loc28_39) [template = f64]
-// CHECK:STDOUT:       %.loc28_39.2: type = value_of_initializer %float.make_type.loc28_39 [template = f64]
-// CHECK:STDOUT:       %.loc28_39.3: type = converted %float.make_type.loc28_39, %.loc28_39.2 [template = f64]
+// CHECK:STDOUT:     %.loc29_39.1: type = splice_block %.loc29_39.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc29_39: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc29_39: init type = call constants.%Float(%int_64.loc29_39) [template = f64]
+// CHECK:STDOUT:       %.loc29_39.2: type = value_of_initializer %float.make_type.loc29_39 [template = f64]
+// CHECK:STDOUT:       %.loc29_39.3: type = converted %float.make_type.loc29_39, %.loc29_39.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: f64 = bind_name a, %a.param
 // CHECK:STDOUT:     %b.param: f64 = value_param runtime_param1
-// CHECK:STDOUT:     %.loc28_47.1: type = splice_block %.loc28_47.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc28_47: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc28_47: init type = call constants.%Float(%int_64.loc28_47) [template = f64]
-// CHECK:STDOUT:       %.loc28_47.2: type = value_of_initializer %float.make_type.loc28_47 [template = f64]
-// CHECK:STDOUT:       %.loc28_47.3: type = converted %float.make_type.loc28_47, %.loc28_47.2 [template = f64]
+// CHECK:STDOUT:     %.loc29_47.1: type = splice_block %.loc29_47.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc29_47: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc29_47: init type = call constants.%Float(%int_64.loc29_47) [template = f64]
+// CHECK:STDOUT:       %.loc29_47.2: type = value_of_initializer %float.make_type.loc29_47 [template = f64]
+// CHECK:STDOUT:       %.loc29_47.3: type = converted %float.make_type.loc29_47, %.loc29_47.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %b: f64 = bind_name b, %b.param
 // CHECK:STDOUT:     %return.param: ref bool = out_param runtime_param2
@@ -445,9 +446,9 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:   %TooFew.ref: %TooFew.type = name_ref TooFew, file.%TooFew.decl [template = constants.%TooFew]
 // CHECK:STDOUT:   %a.ref: f64 = name_ref a, %a
 // CHECK:STDOUT:   %TooFew.call: init f64 = call %TooFew.ref(%a.ref)
-// CHECK:STDOUT:   %.loc21_19.1: f64 = value_of_initializer %TooFew.call
-// CHECK:STDOUT:   %.loc21_19.2: f64 = converted %TooFew.call, %.loc21_19.1
-// CHECK:STDOUT:   return %.loc21_19.2
+// CHECK:STDOUT:   %.loc22_19.1: f64 = value_of_initializer %TooFew.call
+// CHECK:STDOUT:   %.loc22_19.2: f64 = converted %TooFew.call, %.loc22_19.1
+// CHECK:STDOUT:   return %.loc22_19.2
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @RuntimeCallIsValidTooMany(%a.param_patt: f64, %b.param_patt: f64, %c.param_patt: f64) -> f64 {
@@ -457,9 +458,9 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:   %b.ref: f64 = name_ref b, %b
 // CHECK:STDOUT:   %c.ref: f64 = name_ref c, %c
 // CHECK:STDOUT:   %TooMany.call: init f64 = call %TooMany.ref(%a.ref, %b.ref, %c.ref)
-// CHECK:STDOUT:   %.loc25_26.1: f64 = value_of_initializer %TooMany.call
-// CHECK:STDOUT:   %.loc25_26.2: f64 = converted %TooMany.call, %.loc25_26.1
-// CHECK:STDOUT:   return %.loc25_26.2
+// CHECK:STDOUT:   %.loc26_26.1: f64 = value_of_initializer %TooMany.call
+// CHECK:STDOUT:   %.loc26_26.2: f64 = converted %TooMany.call, %.loc26_26.1
+// CHECK:STDOUT:   return %.loc26_26.2
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @RuntimeCallIsValidBadReturnType(%a.param_patt: f64, %b.param_patt: f64) -> bool {
@@ -468,8 +469,8 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:   %a.ref: f64 = name_ref a, %a
 // CHECK:STDOUT:   %b.ref: f64 = name_ref b, %b
 // CHECK:STDOUT:   %BadReturnType.call: init bool = call %BadReturnType.ref(%a.ref, %b.ref)
-// CHECK:STDOUT:   %.loc29_29.1: bool = value_of_initializer %BadReturnType.call
-// CHECK:STDOUT:   %.loc29_29.2: bool = converted %BadReturnType.call, %.loc29_29.1
-// CHECK:STDOUT:   return %.loc29_29.2
+// CHECK:STDOUT:   %.loc30_29.1: bool = value_of_initializer %BadReturnType.call
+// CHECK:STDOUT:   %.loc30_29.2: bool = converted %BadReturnType.call, %.loc30_29.1
+// CHECK:STDOUT:   return %.loc30_29.2
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/builtins/float/negate.carbon b/toolchain/check/testdata/builtins/float/negate.carbon
index 80a72e3b30c2..6f4100994e25 100644
--- a/toolchain/check/testdata/builtins/float/negate.carbon
+++ b/toolchain/check/testdata/builtins/float/negate.carbon
@@ -62,12 +62,13 @@ fn RuntimeCallIsValidTooMany(a: f64, b: f64, c: f64) -> f64 {
 }
 
 fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
-  // CHECK:STDERR: fail_bad_decl.carbon:[[@LINE+6]]:10: error: 2 arguments passed to function expecting 1 argument [CallArgCountMismatch]
+  // CHECK:STDERR: fail_bad_decl.carbon:[[@LINE+7]]:10: error: 2 arguments passed to function expecting 1 argument [CallArgCountMismatch]
   // CHECK:STDERR:   return BadReturnType(a, b);
   // CHECK:STDERR:          ^~~~~~~~~~~~~~~~~~~
   // CHECK:STDERR: fail_bad_decl.carbon:[[@LINE-29]]:1: note: calling function declared here [InCallToEntity]
   // CHECK:STDERR: fn BadReturnType(a: f64) -> bool = "float.negate";
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   return BadReturnType(a, b);
 }
 
diff --git a/toolchain/check/testdata/builtins/float/neq.carbon b/toolchain/check/testdata/builtins/float/neq.carbon
index ea329f36962d..06c9c60d0901 100644
--- a/toolchain/check/testdata/builtins/float/neq.carbon
+++ b/toolchain/check/testdata/builtins/float/neq.carbon
@@ -28,9 +28,10 @@ fn RuntimeCallIsValid(a: f64, b: f64) -> bool {
 
 package FailBadDecl;
 
-// CHECK:STDERR: fail_bad_decl.carbon:[[@LINE+3]]:1: error: invalid signature for builtin function "float.neq" [InvalidBuiltinSignature]
+// CHECK:STDERR: fail_bad_decl.carbon:[[@LINE+4]]:1: error: invalid signature for builtin function "float.neq" [InvalidBuiltinSignature]
 // CHECK:STDERR: fn WrongResult(a: f64, b: f64) -> f64 = "float.neq";
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 fn WrongResult(a: f64, b: f64) -> f64 = "float.neq";
 
 // CHECK:STDOUT: --- float_neq.carbon
@@ -251,24 +252,24 @@ fn WrongResult(a: f64, b: f64) -> f64 = "float.neq";
 // CHECK:STDOUT:     %return.patt: f64 = return_slot_pattern
 // CHECK:STDOUT:     %return.param_patt: f64 = out_param_pattern %return.patt, runtime_param2
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %int_64.loc7_35: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:     %float.make_type.loc7_35: init type = call constants.%Float(%int_64.loc7_35) [template = f64]
-// CHECK:STDOUT:     %.loc7_35.1: type = value_of_initializer %float.make_type.loc7_35 [template = f64]
-// CHECK:STDOUT:     %.loc7_35.2: type = converted %float.make_type.loc7_35, %.loc7_35.1 [template = f64]
+// CHECK:STDOUT:     %int_64.loc8_35: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:     %float.make_type.loc8_35: init type = call constants.%Float(%int_64.loc8_35) [template = f64]
+// CHECK:STDOUT:     %.loc8_35.1: type = value_of_initializer %float.make_type.loc8_35 [template = f64]
+// CHECK:STDOUT:     %.loc8_35.2: type = converted %float.make_type.loc8_35, %.loc8_35.1 [template = f64]
 // CHECK:STDOUT:     %a.param: f64 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc7_19.1: type = splice_block %.loc7_19.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc7_19: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc7_19: init type = call constants.%Float(%int_64.loc7_19) [template = f64]
-// CHECK:STDOUT:       %.loc7_19.2: type = value_of_initializer %float.make_type.loc7_19 [template = f64]
-// CHECK:STDOUT:       %.loc7_19.3: type = converted %float.make_type.loc7_19, %.loc7_19.2 [template = f64]
+// CHECK:STDOUT:     %.loc8_19.1: type = splice_block %.loc8_19.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc8_19: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc8_19: init type = call constants.%Float(%int_64.loc8_19) [template = f64]
+// CHECK:STDOUT:       %.loc8_19.2: type = value_of_initializer %float.make_type.loc8_19 [template = f64]
+// CHECK:STDOUT:       %.loc8_19.3: type = converted %float.make_type.loc8_19, %.loc8_19.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: f64 = bind_name a, %a.param
 // CHECK:STDOUT:     %b.param: f64 = value_param runtime_param1
-// CHECK:STDOUT:     %.loc7_27.1: type = splice_block %.loc7_27.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc7_27: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc7_27: init type = call constants.%Float(%int_64.loc7_27) [template = f64]
-// CHECK:STDOUT:       %.loc7_27.2: type = value_of_initializer %float.make_type.loc7_27 [template = f64]
-// CHECK:STDOUT:       %.loc7_27.3: type = converted %float.make_type.loc7_27, %.loc7_27.2 [template = f64]
+// CHECK:STDOUT:     %.loc8_27.1: type = splice_block %.loc8_27.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc8_27: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc8_27: init type = call constants.%Float(%int_64.loc8_27) [template = f64]
+// CHECK:STDOUT:       %.loc8_27.2: type = value_of_initializer %float.make_type.loc8_27 [template = f64]
+// CHECK:STDOUT:       %.loc8_27.3: type = converted %float.make_type.loc8_27, %.loc8_27.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %b: f64 = bind_name b, %b.param
 // CHECK:STDOUT:     %return.param: ref f64 = out_param runtime_param2
diff --git a/toolchain/check/testdata/builtins/float/sub.carbon b/toolchain/check/testdata/builtins/float/sub.carbon
index 23f0b72356b9..cefc7dddcaa8 100644
--- a/toolchain/check/testdata/builtins/float/sub.carbon
+++ b/toolchain/check/testdata/builtins/float/sub.carbon
@@ -32,9 +32,10 @@ fn TooFew(a: f64) -> f64 = "float.sub";
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
 fn TooMany(a: f64, b: f64, c: f64) -> f64 = "float.sub";
-// CHECK:STDERR: fail_bad_decl.carbon:[[@LINE+3]]:1: error: invalid signature for builtin function "float.sub" [InvalidBuiltinSignature]
+// CHECK:STDERR: fail_bad_decl.carbon:[[@LINE+4]]:1: error: invalid signature for builtin function "float.sub" [InvalidBuiltinSignature]
 // CHECK:STDERR: fn BadReturnType(a: f64, b: f64) -> bool = "float.sub";
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 fn BadReturnType(a: f64, b: f64) -> bool = "float.sub";
 fn JustRight(a: f64, b: f64) -> f64 = "float.sub";
 
@@ -286,22 +287,22 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:     %return.param_patt: bool = out_param_pattern %return.patt, runtime_param2
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %bool.make_type: init type = call constants.%Bool() [template = bool]
-// CHECK:STDOUT:     %.loc17_37.1: type = value_of_initializer %bool.make_type [template = bool]
-// CHECK:STDOUT:     %.loc17_37.2: type = converted %bool.make_type, %.loc17_37.1 [template = bool]
+// CHECK:STDOUT:     %.loc18_37.1: type = value_of_initializer %bool.make_type [template = bool]
+// CHECK:STDOUT:     %.loc18_37.2: type = converted %bool.make_type, %.loc18_37.1 [template = bool]
 // CHECK:STDOUT:     %a.param: f64 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc17_21.1: type = splice_block %.loc17_21.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc17_21: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc17_21: init type = call constants.%Float(%int_64.loc17_21) [template = f64]
-// CHECK:STDOUT:       %.loc17_21.2: type = value_of_initializer %float.make_type.loc17_21 [template = f64]
-// CHECK:STDOUT:       %.loc17_21.3: type = converted %float.make_type.loc17_21, %.loc17_21.2 [template = f64]
+// CHECK:STDOUT:     %.loc18_21.1: type = splice_block %.loc18_21.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc18_21: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc18_21: init type = call constants.%Float(%int_64.loc18_21) [template = f64]
+// CHECK:STDOUT:       %.loc18_21.2: type = value_of_initializer %float.make_type.loc18_21 [template = f64]
+// CHECK:STDOUT:       %.loc18_21.3: type = converted %float.make_type.loc18_21, %.loc18_21.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: f64 = bind_name a, %a.param
 // CHECK:STDOUT:     %b.param: f64 = value_param runtime_param1
-// CHECK:STDOUT:     %.loc17_29.1: type = splice_block %.loc17_29.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc17_29: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc17_29: init type = call constants.%Float(%int_64.loc17_29) [template = f64]
-// CHECK:STDOUT:       %.loc17_29.2: type = value_of_initializer %float.make_type.loc17_29 [template = f64]
-// CHECK:STDOUT:       %.loc17_29.3: type = converted %float.make_type.loc17_29, %.loc17_29.2 [template = f64]
+// CHECK:STDOUT:     %.loc18_29.1: type = splice_block %.loc18_29.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc18_29: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc18_29: init type = call constants.%Float(%int_64.loc18_29) [template = f64]
+// CHECK:STDOUT:       %.loc18_29.2: type = value_of_initializer %float.make_type.loc18_29 [template = f64]
+// CHECK:STDOUT:       %.loc18_29.3: type = converted %float.make_type.loc18_29, %.loc18_29.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %b: f64 = bind_name b, %b.param
 // CHECK:STDOUT:     %return.param: ref bool = out_param runtime_param2
@@ -315,24 +316,24 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:     %return.patt: f64 = return_slot_pattern
 // CHECK:STDOUT:     %return.param_patt: f64 = out_param_pattern %return.patt, runtime_param2
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %int_64.loc18_33: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:     %float.make_type.loc18_33: init type = call constants.%Float(%int_64.loc18_33) [template = f64]
-// CHECK:STDOUT:     %.loc18_33.1: type = value_of_initializer %float.make_type.loc18_33 [template = f64]
-// CHECK:STDOUT:     %.loc18_33.2: type = converted %float.make_type.loc18_33, %.loc18_33.1 [template = f64]
+// CHECK:STDOUT:     %int_64.loc19_33: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:     %float.make_type.loc19_33: init type = call constants.%Float(%int_64.loc19_33) [template = f64]
+// CHECK:STDOUT:     %.loc19_33.1: type = value_of_initializer %float.make_type.loc19_33 [template = f64]
+// CHECK:STDOUT:     %.loc19_33.2: type = converted %float.make_type.loc19_33, %.loc19_33.1 [template = f64]
 // CHECK:STDOUT:     %a.param: f64 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc18_17.1: type = splice_block %.loc18_17.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc18_17: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc18_17: init type = call constants.%Float(%int_64.loc18_17) [template = f64]
-// CHECK:STDOUT:       %.loc18_17.2: type = value_of_initializer %float.make_type.loc18_17 [template = f64]
-// CHECK:STDOUT:       %.loc18_17.3: type = converted %float.make_type.loc18_17, %.loc18_17.2 [template = f64]
+// CHECK:STDOUT:     %.loc19_17.1: type = splice_block %.loc19_17.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc19_17: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc19_17: init type = call constants.%Float(%int_64.loc19_17) [template = f64]
+// CHECK:STDOUT:       %.loc19_17.2: type = value_of_initializer %float.make_type.loc19_17 [template = f64]
+// CHECK:STDOUT:       %.loc19_17.3: type = converted %float.make_type.loc19_17, %.loc19_17.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: f64 = bind_name a, %a.param
 // CHECK:STDOUT:     %b.param: f64 = value_param runtime_param1
-// CHECK:STDOUT:     %.loc18_25.1: type = splice_block %.loc18_25.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc18_25: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc18_25: init type = call constants.%Float(%int_64.loc18_25) [template = f64]
-// CHECK:STDOUT:       %.loc18_25.2: type = value_of_initializer %float.make_type.loc18_25 [template = f64]
-// CHECK:STDOUT:       %.loc18_25.3: type = converted %float.make_type.loc18_25, %.loc18_25.2 [template = f64]
+// CHECK:STDOUT:     %.loc19_25.1: type = splice_block %.loc19_25.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc19_25: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc19_25: init type = call constants.%Float(%int_64.loc19_25) [template = f64]
+// CHECK:STDOUT:       %.loc19_25.2: type = value_of_initializer %float.make_type.loc19_25 [template = f64]
+// CHECK:STDOUT:       %.loc19_25.3: type = converted %float.make_type.loc19_25, %.loc19_25.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %b: f64 = bind_name b, %b.param
 // CHECK:STDOUT:     %return.param: ref f64 = out_param runtime_param2
@@ -344,16 +345,16 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:     %return.patt: f64 = return_slot_pattern
 // CHECK:STDOUT:     %return.param_patt: f64 = out_param_pattern %return.patt, runtime_param1
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %int_64.loc20_40: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:     %float.make_type.loc20_40: init type = call constants.%Float(%int_64.loc20_40) [template = f64]
-// CHECK:STDOUT:     %.loc20_40.1: type = value_of_initializer %float.make_type.loc20_40 [template = f64]
-// CHECK:STDOUT:     %.loc20_40.2: type = converted %float.make_type.loc20_40, %.loc20_40.1 [template = f64]
+// CHECK:STDOUT:     %int_64.loc21_40: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:     %float.make_type.loc21_40: init type = call constants.%Float(%int_64.loc21_40) [template = f64]
+// CHECK:STDOUT:     %.loc21_40.1: type = value_of_initializer %float.make_type.loc21_40 [template = f64]
+// CHECK:STDOUT:     %.loc21_40.2: type = converted %float.make_type.loc21_40, %.loc21_40.1 [template = f64]
 // CHECK:STDOUT:     %a.param: f64 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc20_32.1: type = splice_block %.loc20_32.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc20_32: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc20_32: init type = call constants.%Float(%int_64.loc20_32) [template = f64]
-// CHECK:STDOUT:       %.loc20_32.2: type = value_of_initializer %float.make_type.loc20_32 [template = f64]
-// CHECK:STDOUT:       %.loc20_32.3: type = converted %float.make_type.loc20_32, %.loc20_32.2 [template = f64]
+// CHECK:STDOUT:     %.loc21_32.1: type = splice_block %.loc21_32.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc21_32: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc21_32: init type = call constants.%Float(%int_64.loc21_32) [template = f64]
+// CHECK:STDOUT:       %.loc21_32.2: type = value_of_initializer %float.make_type.loc21_32 [template = f64]
+// CHECK:STDOUT:       %.loc21_32.3: type = converted %float.make_type.loc21_32, %.loc21_32.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: f64 = bind_name a, %a.param
 // CHECK:STDOUT:     %return.param: ref f64 = out_param runtime_param1
@@ -369,32 +370,32 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:     %return.patt: f64 = return_slot_pattern
 // CHECK:STDOUT:     %return.param_patt: f64 = out_param_pattern %return.patt, runtime_param3
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %int_64.loc24_57: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:     %float.make_type.loc24_57: init type = call constants.%Float(%int_64.loc24_57) [template = f64]
-// CHECK:STDOUT:     %.loc24_57.1: type = value_of_initializer %float.make_type.loc24_57 [template = f64]
-// CHECK:STDOUT:     %.loc24_57.2: type = converted %float.make_type.loc24_57, %.loc24_57.1 [template = f64]
+// CHECK:STDOUT:     %int_64.loc25_57: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:     %float.make_type.loc25_57: init type = call constants.%Float(%int_64.loc25_57) [template = f64]
+// CHECK:STDOUT:     %.loc25_57.1: type = value_of_initializer %float.make_type.loc25_57 [template = f64]
+// CHECK:STDOUT:     %.loc25_57.2: type = converted %float.make_type.loc25_57, %.loc25_57.1 [template = f64]
 // CHECK:STDOUT:     %a.param: f64 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc24_33.1: type = splice_block %.loc24_33.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc24_33: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc24_33: init type = call constants.%Float(%int_64.loc24_33) [template = f64]
-// CHECK:STDOUT:       %.loc24_33.2: type = value_of_initializer %float.make_type.loc24_33 [template = f64]
-// CHECK:STDOUT:       %.loc24_33.3: type = converted %float.make_type.loc24_33, %.loc24_33.2 [template = f64]
+// CHECK:STDOUT:     %.loc25_33.1: type = splice_block %.loc25_33.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc25_33: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc25_33: init type = call constants.%Float(%int_64.loc25_33) [template = f64]
+// CHECK:STDOUT:       %.loc25_33.2: type = value_of_initializer %float.make_type.loc25_33 [template = f64]
+// CHECK:STDOUT:       %.loc25_33.3: type = converted %float.make_type.loc25_33, %.loc25_33.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: f64 = bind_name a, %a.param
 // CHECK:STDOUT:     %b.param: f64 = value_param runtime_param1
-// CHECK:STDOUT:     %.loc24_41.1: type = splice_block %.loc24_41.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc24_41: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc24_41: init type = call constants.%Float(%int_64.loc24_41) [template = f64]
-// CHECK:STDOUT:       %.loc24_41.2: type = value_of_initializer %float.make_type.loc24_41 [template = f64]
-// CHECK:STDOUT:       %.loc24_41.3: type = converted %float.make_type.loc24_41, %.loc24_41.2 [template = f64]
+// CHECK:STDOUT:     %.loc25_41.1: type = splice_block %.loc25_41.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc25_41: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc25_41: init type = call constants.%Float(%int_64.loc25_41) [template = f64]
+// CHECK:STDOUT:       %.loc25_41.2: type = value_of_initializer %float.make_type.loc25_41 [template = f64]
+// CHECK:STDOUT:       %.loc25_41.3: type = converted %float.make_type.loc25_41, %.loc25_41.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %b: f64 = bind_name b, %b.param
 // CHECK:STDOUT:     %c.param: f64 = value_param runtime_param2
-// CHECK:STDOUT:     %.loc24_49.1: type = splice_block %.loc24_49.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc24_49: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc24_49: init type = call constants.%Float(%int_64.loc24_49) [template = f64]
-// CHECK:STDOUT:       %.loc24_49.2: type = value_of_initializer %float.make_type.loc24_49 [template = f64]
-// CHECK:STDOUT:       %.loc24_49.3: type = converted %float.make_type.loc24_49, %.loc24_49.2 [template = f64]
+// CHECK:STDOUT:     %.loc25_49.1: type = splice_block %.loc25_49.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc25_49: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc25_49: init type = call constants.%Float(%int_64.loc25_49) [template = f64]
+// CHECK:STDOUT:       %.loc25_49.2: type = value_of_initializer %float.make_type.loc25_49 [template = f64]
+// CHECK:STDOUT:       %.loc25_49.3: type = converted %float.make_type.loc25_49, %.loc25_49.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %c: f64 = bind_name c, %c.param
 // CHECK:STDOUT:     %return.param: ref f64 = out_param runtime_param3
@@ -409,22 +410,22 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:     %return.param_patt: bool = out_param_pattern %return.patt, runtime_param2
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %bool.make_type: init type = call constants.%Bool() [template = bool]
-// CHECK:STDOUT:     %.loc28_55.1: type = value_of_initializer %bool.make_type [template = bool]
-// CHECK:STDOUT:     %.loc28_55.2: type = converted %bool.make_type, %.loc28_55.1 [template = bool]
+// CHECK:STDOUT:     %.loc29_55.1: type = value_of_initializer %bool.make_type [template = bool]
+// CHECK:STDOUT:     %.loc29_55.2: type = converted %bool.make_type, %.loc29_55.1 [template = bool]
 // CHECK:STDOUT:     %a.param: f64 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc28_39.1: type = splice_block %.loc28_39.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc28_39: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc28_39: init type = call constants.%Float(%int_64.loc28_39) [template = f64]
-// CHECK:STDOUT:       %.loc28_39.2: type = value_of_initializer %float.make_type.loc28_39 [template = f64]
-// CHECK:STDOUT:       %.loc28_39.3: type = converted %float.make_type.loc28_39, %.loc28_39.2 [template = f64]
+// CHECK:STDOUT:     %.loc29_39.1: type = splice_block %.loc29_39.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc29_39: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc29_39: init type = call constants.%Float(%int_64.loc29_39) [template = f64]
+// CHECK:STDOUT:       %.loc29_39.2: type = value_of_initializer %float.make_type.loc29_39 [template = f64]
+// CHECK:STDOUT:       %.loc29_39.3: type = converted %float.make_type.loc29_39, %.loc29_39.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: f64 = bind_name a, %a.param
 // CHECK:STDOUT:     %b.param: f64 = value_param runtime_param1
-// CHECK:STDOUT:     %.loc28_47.1: type = splice_block %.loc28_47.3 [template = f64] {
-// CHECK:STDOUT:       %int_64.loc28_47: Core.IntLiteral = int_value 64 [template = constants.%int_64]
-// CHECK:STDOUT:       %float.make_type.loc28_47: init type = call constants.%Float(%int_64.loc28_47) [template = f64]
-// CHECK:STDOUT:       %.loc28_47.2: type = value_of_initializer %float.make_type.loc28_47 [template = f64]
-// CHECK:STDOUT:       %.loc28_47.3: type = converted %float.make_type.loc28_47, %.loc28_47.2 [template = f64]
+// CHECK:STDOUT:     %.loc29_47.1: type = splice_block %.loc29_47.3 [template = f64] {
+// CHECK:STDOUT:       %int_64.loc29_47: Core.IntLiteral = int_value 64 [template = constants.%int_64]
+// CHECK:STDOUT:       %float.make_type.loc29_47: init type = call constants.%Float(%int_64.loc29_47) [template = f64]
+// CHECK:STDOUT:       %.loc29_47.2: type = value_of_initializer %float.make_type.loc29_47 [template = f64]
+// CHECK:STDOUT:       %.loc29_47.3: type = converted %float.make_type.loc29_47, %.loc29_47.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %b: f64 = bind_name b, %b.param
 // CHECK:STDOUT:     %return.param: ref bool = out_param runtime_param2
@@ -445,9 +446,9 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:   %TooFew.ref: %TooFew.type = name_ref TooFew, file.%TooFew.decl [template = constants.%TooFew]
 // CHECK:STDOUT:   %a.ref: f64 = name_ref a, %a
 // CHECK:STDOUT:   %TooFew.call: init f64 = call %TooFew.ref(%a.ref)
-// CHECK:STDOUT:   %.loc21_19.1: f64 = value_of_initializer %TooFew.call
-// CHECK:STDOUT:   %.loc21_19.2: f64 = converted %TooFew.call, %.loc21_19.1
-// CHECK:STDOUT:   return %.loc21_19.2
+// CHECK:STDOUT:   %.loc22_19.1: f64 = value_of_initializer %TooFew.call
+// CHECK:STDOUT:   %.loc22_19.2: f64 = converted %TooFew.call, %.loc22_19.1
+// CHECK:STDOUT:   return %.loc22_19.2
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @RuntimeCallIsValidTooMany(%a.param_patt: f64, %b.param_patt: f64, %c.param_patt: f64) -> f64 {
@@ -457,9 +458,9 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:   %b.ref: f64 = name_ref b, %b
 // CHECK:STDOUT:   %c.ref: f64 = name_ref c, %c
 // CHECK:STDOUT:   %TooMany.call: init f64 = call %TooMany.ref(%a.ref, %b.ref, %c.ref)
-// CHECK:STDOUT:   %.loc25_26.1: f64 = value_of_initializer %TooMany.call
-// CHECK:STDOUT:   %.loc25_26.2: f64 = converted %TooMany.call, %.loc25_26.1
-// CHECK:STDOUT:   return %.loc25_26.2
+// CHECK:STDOUT:   %.loc26_26.1: f64 = value_of_initializer %TooMany.call
+// CHECK:STDOUT:   %.loc26_26.2: f64 = converted %TooMany.call, %.loc26_26.1
+// CHECK:STDOUT:   return %.loc26_26.2
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @RuntimeCallIsValidBadReturnType(%a.param_patt: f64, %b.param_patt: f64) -> bool {
@@ -468,8 +469,8 @@ fn RuntimeCallIsValidBadReturnType(a: f64, b: f64) -> bool {
 // CHECK:STDOUT:   %a.ref: f64 = name_ref a, %a
 // CHECK:STDOUT:   %b.ref: f64 = name_ref b, %b
 // CHECK:STDOUT:   %BadReturnType.call: init bool = call %BadReturnType.ref(%a.ref, %b.ref)
-// CHECK:STDOUT:   %.loc29_29.1: bool = value_of_initializer %BadReturnType.call
-// CHECK:STDOUT:   %.loc29_29.2: bool = converted %BadReturnType.call, %.loc29_29.1
-// CHECK:STDOUT:   return %.loc29_29.2
+// CHECK:STDOUT:   %.loc30_29.1: bool = value_of_initializer %BadReturnType.call
+// CHECK:STDOUT:   %.loc30_29.2: bool = converted %BadReturnType.call, %.loc30_29.1
+// CHECK:STDOUT:   return %.loc30_29.2
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/builtins/int/and.carbon b/toolchain/check/testdata/builtins/int/and.carbon
index 944f35971a04..f624ff011d09 100644
--- a/toolchain/check/testdata/builtins/int/and.carbon
+++ b/toolchain/check/testdata/builtins/int/and.carbon
@@ -111,11 +111,12 @@ fn Test(n: Core.IntLiteral()) {
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   // CHECK:STDERR:
   And(1, n);
-  // CHECK:STDERR: fail_runtime_literal.carbon:[[@LINE+6]]:3: error: non-constant call to compile-time-only function [NonConstantCallToCompTimeOnlyFunction]
+  // CHECK:STDERR: fail_runtime_literal.carbon:[[@LINE+7]]:3: error: non-constant call to compile-time-only function [NonConstantCallToCompTimeOnlyFunction]
   // CHECK:STDERR:   And(n, n);
   // CHECK:STDERR:   ^~~~~~~~~
   // CHECK:STDERR: fail_runtime_literal.carbon:[[@LINE-24]]:1: note: compile-time-only function declared here [CompTimeOnlyFunctionHere]
   // CHECK:STDERR: fn And(a: Core.IntLiteral(), b: Core.IntLiteral()) -> Core.IntLiteral() = "int.and";
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   And(n, n);
 }
diff --git a/toolchain/check/testdata/builtins/int/complement.carbon b/toolchain/check/testdata/builtins/int/complement.carbon
index 7fddbd691d72..a40d2c6960ba 100644
--- a/toolchain/check/testdata/builtins/int/complement.carbon
+++ b/toolchain/check/testdata/builtins/int/complement.carbon
@@ -50,11 +50,12 @@ library "[[@TEST_NAME]]";
 fn Complement(a: Core.IntLiteral()) -> Core.IntLiteral() = "int.complement";
 
 fn F(a: Core.IntLiteral()) -> Core.IntLiteral() {
-  // CHECK:STDERR: fail_literal_runtime.carbon:[[@LINE+6]]:10: error: non-constant call to compile-time-only function [NonConstantCallToCompTimeOnlyFunction]
+  // CHECK:STDERR: fail_literal_runtime.carbon:[[@LINE+7]]:10: error: non-constant call to compile-time-only function [NonConstantCallToCompTimeOnlyFunction]
   // CHECK:STDERR:   return Complement(a);
   // CHECK:STDERR:          ^~~~~~~~~~~~~
   // CHECK:STDERR: fail_literal_runtime.carbon:[[@LINE-6]]:1: note: compile-time-only function declared here [CompTimeOnlyFunctionHere]
   // CHECK:STDERR: fn Complement(a: Core.IntLiteral()) -> Core.IntLiteral() = "int.complement";
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   return Complement(a);
 }
diff --git a/toolchain/check/testdata/builtins/int/convert.carbon b/toolchain/check/testdata/builtins/int/convert.carbon
index 91970fadfaee..624472f71dd7 100644
--- a/toolchain/check/testdata/builtins/int/convert.carbon
+++ b/toolchain/check/testdata/builtins/int/convert.carbon
@@ -216,11 +216,12 @@ import library "int_ops";
 
 let not_constant: Core.IntLiteral() = 0;
 
-// CHECK:STDERR: fail_not_constant.carbon:[[@LINE+7]]:33: error: non-constant call to compile-time-only function [NonConstantCallToCompTimeOnlyFunction]
+// CHECK:STDERR: fail_not_constant.carbon:[[@LINE+8]]:33: error: non-constant call to compile-time-only function [NonConstantCallToCompTimeOnlyFunction]
 // CHECK:STDERR: let convert_not_constant: i16 = IntLiteralToInt16(not_constant);
 // CHECK:STDERR:                                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_not_constant.carbon:[[@LINE-7]]:1: in import [InImport]
 // CHECK:STDERR: int_ops.carbon:16:1: note: compile-time-only function declared here [CompTimeOnlyFunctionHere]
 // CHECK:STDERR: fn IntLiteralToInt16(a: Core.IntLiteral()) -> i16 = "int.convert";
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 let convert_not_constant: i16 = IntLiteralToInt16(not_constant);
diff --git a/toolchain/check/testdata/builtins/int/convert_checked.carbon b/toolchain/check/testdata/builtins/int/convert_checked.carbon
index ec0a6a84f18f..83201ee3997f 100644
--- a/toolchain/check/testdata/builtins/int/convert_checked.carbon
+++ b/toolchain/check/testdata/builtins/int/convert_checked.carbon
@@ -241,11 +241,12 @@ let convert_not_constant_narrow: i16 = Int32ToInt16(not_constant);
 // CHECK:STDERR:
 let convert_not_constant_same: i32 = Int32ToInt32(not_constant);
 
-// CHECK:STDERR: fail_not_constant.carbon:[[@LINE+7]]:39: error: non-constant call to compile-time-only function [NonConstantCallToCompTimeOnlyFunction]
+// CHECK:STDERR: fail_not_constant.carbon:[[@LINE+8]]:39: error: non-constant call to compile-time-only function [NonConstantCallToCompTimeOnlyFunction]
 // CHECK:STDERR: let convert_not_constant_widen: i64 = Int32ToInt64(not_constant);
 // CHECK:STDERR:                                       ^~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_not_constant.carbon:[[@LINE-27]]:1: in import [InImport]
 // CHECK:STDERR: int_ops.carbon:26:1: note: compile-time-only function declared here [CompTimeOnlyFunctionHere]
 // CHECK:STDERR: fn Int32ToInt64(a: i32) -> i64 = "int.convert_checked";
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 let convert_not_constant_widen: i64 = Int32ToInt64(not_constant);
diff --git a/toolchain/check/testdata/builtins/int/eq.carbon b/toolchain/check/testdata/builtins/int/eq.carbon
index efea56401882..ebc625f9288b 100644
--- a/toolchain/check/testdata/builtins/int/eq.carbon
+++ b/toolchain/check/testdata/builtins/int/eq.carbon
@@ -95,11 +95,12 @@ fn Test(n: Core.IntLiteral()) {
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   // CHECK:STDERR:
   Eq(1, n);
-  // CHECK:STDERR: fail_runtime_literal.carbon:[[@LINE+6]]:3: error: non-constant call to compile-time-only function [NonConstantCallToCompTimeOnlyFunction]
+  // CHECK:STDERR: fail_runtime_literal.carbon:[[@LINE+7]]:3: error: non-constant call to compile-time-only function [NonConstantCallToCompTimeOnlyFunction]
   // CHECK:STDERR:   Eq(n, n);
   // CHECK:STDERR:   ^~~~~~~~
   // CHECK:STDERR: fail_runtime_literal.carbon:[[@LINE-24]]:1: note: compile-time-only function declared here [CompTimeOnlyFunctionHere]
   // CHECK:STDERR: fn Eq(a: Core.IntLiteral(), b: Core.IntLiteral()) -> bool = "int.eq";
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   Eq(n, n);
 }
diff --git a/toolchain/check/testdata/builtins/int/left_shift.carbon b/toolchain/check/testdata/builtins/int/left_shift.carbon
index b749abe4942f..e47f73cb5a32 100644
--- a/toolchain/check/testdata/builtins/int/left_shift.carbon
+++ b/toolchain/check/testdata/builtins/int/left_shift.carbon
@@ -215,10 +215,11 @@ let bad2: Core.IntLiteral() = LeftShiftOfLit(a_lit, an_i32);
 let bad3: i32 = LeftShiftByLit(an_i32, 12);
 
 // TODO: This could be valid because we don't actually need the return value at runtime.
-// CHECK:STDERR: fail_comp_time_only_shift.carbon:[[@LINE+6]]:31: error: non-constant call to compile-time-only function [NonConstantCallToCompTimeOnlyFunction]
+// CHECK:STDERR: fail_comp_time_only_shift.carbon:[[@LINE+7]]:31: error: non-constant call to compile-time-only function [NonConstantCallToCompTimeOnlyFunction]
 // CHECK:STDERR: let bad4: Core.IntLiteral() = LeftShiftOfLit(12, an_i32);
 // CHECK:STDERR:                               ^~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_comp_time_only_shift.carbon:[[@LINE-39]]:1: note: compile-time-only function declared here [CompTimeOnlyFunctionHere]
 // CHECK:STDERR: fn LeftShiftOfLit(a: Core.IntLiteral(), b: i32) -> Core.IntLiteral() = "int.left_shift";
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 let bad4: Core.IntLiteral() = LeftShiftOfLit(12, an_i32);
diff --git a/toolchain/check/testdata/builtins/int/less_eq.carbon b/toolchain/check/testdata/builtins/int/less_eq.carbon
index 7b170bfd06de..72a4daa8406d 100644
--- a/toolchain/check/testdata/builtins/int/less_eq.carbon
+++ b/toolchain/check/testdata/builtins/int/less_eq.carbon
@@ -93,11 +93,12 @@ fn Test(n: Core.IntLiteral()) {
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   // CHECK:STDERR:
   LessEq(1, n);
-  // CHECK:STDERR: fail_runtime_literal.carbon:[[@LINE+6]]:3: error: non-constant call to compile-time-only function [NonConstantCallToCompTimeOnlyFunction]
+  // CHECK:STDERR: fail_runtime_literal.carbon:[[@LINE+7]]:3: error: non-constant call to compile-time-only function [NonConstantCallToCompTimeOnlyFunction]
   // CHECK:STDERR:   LessEq(n, n);
   // CHECK:STDERR:   ^~~~~~~~~~~~
   // CHECK:STDERR: fail_runtime_literal.carbon:[[@LINE-24]]:1: note: compile-time-only function declared here [CompTimeOnlyFunctionHere]
   // CHECK:STDERR: fn LessEq(a: Core.IntLiteral(), b: Core.IntLiteral()) -> bool = "int.less_eq";
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   LessEq(n, n);
 }
diff --git a/toolchain/check/testdata/builtins/int/make_type_signed.carbon b/toolchain/check/testdata/builtins/int/make_type_signed.carbon
index d03c14120350..94d13271a191 100644
--- a/toolchain/check/testdata/builtins/int/make_type_signed.carbon
+++ b/toolchain/check/testdata/builtins/int/make_type_signed.carbon
@@ -86,7 +86,8 @@ library "[[@TEST_NAME]]";
 
 import library "types";
 
-// CHECK:STDERR: fail_oversized.carbon:[[@LINE+3]]:8: error: integer type width of 1000000000 is greater than the maximum supported width of 8388608 [IntWidthTooLarge]
+// CHECK:STDERR: fail_oversized.carbon:[[@LINE+4]]:8: error: integer type width of 1000000000 is greater than the maximum supported width of 8388608 [IntWidthTooLarge]
 // CHECK:STDERR: var m: Int(1000000000);
 // CHECK:STDERR:        ^~~~~~~~~~~~~~~
+// CHECK:STDERR:
 var m: Int(1000000000);
diff --git a/toolchain/check/testdata/builtins/int/make_type_unsigned.carbon b/toolchain/check/testdata/builtins/int/make_type_unsigned.carbon
index 6fc8961c2a12..44a1511e7291 100644
--- a/toolchain/check/testdata/builtins/int/make_type_unsigned.carbon
+++ b/toolchain/check/testdata/builtins/int/make_type_unsigned.carbon
@@ -67,7 +67,8 @@ library "[[@TEST_NAME]]";
 
 import library "types";
 
-// CHECK:STDERR: fail_oversized.carbon:[[@LINE+3]]:8: error: integer type width of 1000000000 is greater than the maximum supported width of 8388608 [IntWidthTooLarge]
+// CHECK:STDERR: fail_oversized.carbon:[[@LINE+4]]:8: error: integer type width of 1000000000 is greater than the maximum supported width of 8388608 [IntWidthTooLarge]
 // CHECK:STDERR: var m: UInt(1000000000);
 // CHECK:STDERR:        ^~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 var m: UInt(1000000000);
diff --git a/toolchain/check/testdata/builtins/int/right_shift.carbon b/toolchain/check/testdata/builtins/int/right_shift.carbon
index 6581455108fb..0104d41079b9 100644
--- a/toolchain/check/testdata/builtins/int/right_shift.carbon
+++ b/toolchain/check/testdata/builtins/int/right_shift.carbon
@@ -122,7 +122,8 @@ let negative_zero: i32 = RightShift(0, -1);
 // CHECK:STDERR:                                       ^~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
 let negative_lit: Core.IntLiteral() = RightShiftLit(1, -1);
-// CHECK:STDERR: fail_bad_shift.carbon:[[@LINE+3]]:44: error: shift distance negative in `0 >> -1` [CompileTimeShiftNegative]
+// CHECK:STDERR: fail_bad_shift.carbon:[[@LINE+4]]:44: error: shift distance negative in `0 >> -1` [CompileTimeShiftNegative]
 // CHECK:STDERR: let negative_lit_zero: Core.IntLiteral() = RightShiftLit(0, -1);
 // CHECK:STDERR:                                            ^~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 let negative_lit_zero: Core.IntLiteral() = RightShiftLit(0, -1);
diff --git a/toolchain/check/testdata/builtins/int/sadd.carbon b/toolchain/check/testdata/builtins/int/sadd.carbon
index 794ec245313a..45aa2db79c66 100644
--- a/toolchain/check/testdata/builtins/int/sadd.carbon
+++ b/toolchain/check/testdata/builtins/int/sadd.carbon
@@ -138,7 +138,8 @@ package FailOverflow;
 fn Add(a: i32, b: i32) -> i32 = "int.sadd";
 
 let a: i32 = Add(0x7FFFFFFF, 0);
-// CHECK:STDERR: fail_overflow.carbon:[[@LINE+3]]:14: error: integer overflow in calculation `2147483647 + 1` [CompileTimeIntegerOverflow]
+// CHECK:STDERR: fail_overflow.carbon:[[@LINE+4]]:14: error: integer overflow in calculation `2147483647 + 1` [CompileTimeIntegerOverflow]
 // CHECK:STDERR: let b: i32 = Add(0x7FFFFFFF, 1);
 // CHECK:STDERR:              ^~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 let b: i32 = Add(0x7FFFFFFF, 1);
diff --git a/toolchain/check/testdata/builtins/int/sdiv.carbon b/toolchain/check/testdata/builtins/int/sdiv.carbon
index f7c87e61ae4a..3de44450bb88 100644
--- a/toolchain/check/testdata/builtins/int/sdiv.carbon
+++ b/toolchain/check/testdata/builtins/int/sdiv.carbon
@@ -82,7 +82,8 @@ let b: i32 = Div(0, 0);
 // CHECK:STDERR:
 let c: Core.IntLiteral() = DivLit(1, 0);
 
-// CHECK:STDERR: fail_div_by_zero.carbon:[[@LINE+3]]:28: error: division by zero [CompileTimeDivisionByZero]
+// CHECK:STDERR: fail_div_by_zero.carbon:[[@LINE+4]]:28: error: division by zero [CompileTimeDivisionByZero]
 // CHECK:STDERR: let d: Core.IntLiteral() = DivLit(0, 0);
 // CHECK:STDERR:                            ^~~~~~~~~~~~
+// CHECK:STDERR:
 let d: Core.IntLiteral() = DivLit(0, 0);
diff --git a/toolchain/check/testdata/builtins/int/smod.carbon b/toolchain/check/testdata/builtins/int/smod.carbon
index dbcd590aa401..bd15000b6a26 100644
--- a/toolchain/check/testdata/builtins/int/smod.carbon
+++ b/toolchain/check/testdata/builtins/int/smod.carbon
@@ -57,7 +57,8 @@ fn Mod(a: i32, b: i32) -> i32 = "int.smod";
 // CHECK:STDERR:
 let a: i32 = Mod(1, 0);
 
-// CHECK:STDERR: fail_div_by_zero.carbon:[[@LINE+3]]:14: error: division by zero [CompileTimeDivisionByZero]
+// CHECK:STDERR: fail_div_by_zero.carbon:[[@LINE+4]]:14: error: division by zero [CompileTimeDivisionByZero]
 // CHECK:STDERR: let b: i32 = Mod(0, 0);
 // CHECK:STDERR:              ^~~~~~~~~
+// CHECK:STDERR:
 let b: i32 = Mod(0, 0);
diff --git a/toolchain/check/testdata/builtins/int/smul.carbon b/toolchain/check/testdata/builtins/int/smul.carbon
index 403efe866b39..fb436a51f1d5 100644
--- a/toolchain/check/testdata/builtins/int/smul.carbon
+++ b/toolchain/check/testdata/builtins/int/smul.carbon
@@ -66,7 +66,8 @@ package FailOverflow;
 fn Mul(a: i32, b: i32) -> i32 = "int.smul";
 
 let a: i32 = Mul(0x7FFF, 0x10000);
-// CHECK:STDERR: fail_overflow.carbon:[[@LINE+3]]:14: error: integer overflow in calculation `32768 * 65536` [CompileTimeIntegerOverflow]
+// CHECK:STDERR: fail_overflow.carbon:[[@LINE+4]]:14: error: integer overflow in calculation `32768 * 65536` [CompileTimeIntegerOverflow]
 // CHECK:STDERR: let b: i32 = Mul(0x8000, 0x10000);
 // CHECK:STDERR:              ^~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 let b: i32 = Mul(0x8000, 0x10000);
diff --git a/toolchain/check/testdata/builtins/int/snegate.carbon b/toolchain/check/testdata/builtins/int/snegate.carbon
index 93b3d41d66a3..1c5a448f0263 100644
--- a/toolchain/check/testdata/builtins/int/snegate.carbon
+++ b/toolchain/check/testdata/builtins/int/snegate.carbon
@@ -128,7 +128,8 @@ fn Sub(a: i32, b: i32) -> i32 = "int.ssub";
 let a: i32 = Negate(Negate(0x7FFF_FFFF));
 
 // -INT_MIN is too large for i32.
-// CHECK:STDERR: fail_overflow.carbon:[[@LINE+3]]:14: error: integer overflow in negation of -2147483648 [CompileTimeIntegerNegateOverflow]
+// CHECK:STDERR: fail_overflow.carbon:[[@LINE+4]]:14: error: integer overflow in negation of -2147483648 [CompileTimeIntegerNegateOverflow]
 // CHECK:STDERR: let b: i32 = Negate(-0x8000_0000);
 // CHECK:STDERR:              ^~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 let b: i32 = Negate(-0x8000_0000);
diff --git a/toolchain/check/testdata/builtins/int/ssub.carbon b/toolchain/check/testdata/builtins/int/ssub.carbon
index a7cdfe90ca12..a52cad1d39f1 100644
--- a/toolchain/check/testdata/builtins/int/ssub.carbon
+++ b/toolchain/check/testdata/builtins/int/ssub.carbon
@@ -29,7 +29,8 @@ fn Sub(a: i32, b: i32) -> i32 = "int.ssub";
 
 let a: i32 = Sub(0, 0x7FFFFFFF);
 let b: i32 = Sub(Sub(0, 0x7FFFFFFF), 1);
-// CHECK:STDERR: fail_overflow.carbon:[[@LINE+3]]:14: error: integer overflow in calculation `-2147483647 - 2` [CompileTimeIntegerOverflow]
+// CHECK:STDERR: fail_overflow.carbon:[[@LINE+4]]:14: error: integer overflow in calculation `-2147483647 - 2` [CompileTimeIntegerOverflow]
 // CHECK:STDERR: let c: i32 = Sub(Sub(0, 0x7FFFFFFF), 2);
 // CHECK:STDERR:              ^~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 let c: i32 = Sub(Sub(0, 0x7FFFFFFF), 2);
diff --git a/toolchain/check/testdata/builtins/int/uadd.carbon b/toolchain/check/testdata/builtins/int/uadd.carbon
index cd7ac70b6b99..064caa751627 100644
--- a/toolchain/check/testdata/builtins/int/uadd.carbon
+++ b/toolchain/check/testdata/builtins/int/uadd.carbon
@@ -58,12 +58,13 @@ var too_many: [i32; TooMany(1, 2, 3)];
 // CHECK:STDERR:
 var bad_return_type: [i32; BadReturnType(1, 2)];
 
-// CHECK:STDERR: fail_bad_decl.carbon:[[@LINE+6]]:21: error: 3 arguments passed to function expecting 2 arguments [CallArgCountMismatch]
+// CHECK:STDERR: fail_bad_decl.carbon:[[@LINE+7]]:21: error: 3 arguments passed to function expecting 2 arguments [CallArgCountMismatch]
 // CHECK:STDERR: var bad_call: [i32; JustRight(1, 2, 3)];
 // CHECK:STDERR:                     ^~~~~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_bad_decl.carbon:[[@LINE-21]]:1: note: calling function declared here [InCallToEntity]
 // CHECK:STDERR: fn JustRight(a: i32, b: i32) -> i32 = "int.uadd";
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 var bad_call: [i32; JustRight(1, 2, 3)];
 
 fn RuntimeCallIsValidTooFew(a: i32) -> i32 {
diff --git a/toolchain/check/testdata/builtins/int/udiv.carbon b/toolchain/check/testdata/builtins/int/udiv.carbon
index 1efe7a893858..922034530650 100644
--- a/toolchain/check/testdata/builtins/int/udiv.carbon
+++ b/toolchain/check/testdata/builtins/int/udiv.carbon
@@ -50,7 +50,8 @@ fn Div(a: i32, b: i32) -> i32 = "int.udiv";
 // CHECK:STDERR:
 let a: i32 = Div(1, 0);
 
-// CHECK:STDERR: fail_div_by_zero.carbon:[[@LINE+3]]:14: error: division by zero [CompileTimeDivisionByZero]
+// CHECK:STDERR: fail_div_by_zero.carbon:[[@LINE+4]]:14: error: division by zero [CompileTimeDivisionByZero]
 // CHECK:STDERR: let b: i32 = Div(0, 0);
 // CHECK:STDERR:              ^~~~~~~~~
+// CHECK:STDERR:
 let b: i32 = Div(0, 0);
diff --git a/toolchain/check/testdata/builtins/int/umod.carbon b/toolchain/check/testdata/builtins/int/umod.carbon
index dc6067eb2d64..65498af8bea3 100644
--- a/toolchain/check/testdata/builtins/int/umod.carbon
+++ b/toolchain/check/testdata/builtins/int/umod.carbon
@@ -52,7 +52,8 @@ fn Mod(a: i32, b: i32) -> i32 = "int.umod";
 // CHECK:STDERR:
 let a: i32 = Mod(1, 0);
 
-// CHECK:STDERR: fail_div_by_zero.carbon:[[@LINE+3]]:14: error: division by zero [CompileTimeDivisionByZero]
+// CHECK:STDERR: fail_div_by_zero.carbon:[[@LINE+4]]:14: error: division by zero [CompileTimeDivisionByZero]
 // CHECK:STDERR: let b: i32 = Mod(0, 0);
 // CHECK:STDERR:              ^~~~~~~~~
+// CHECK:STDERR:
 let b: i32 = Mod(0, 0);
diff --git a/toolchain/check/testdata/builtins/int/unegate.carbon b/toolchain/check/testdata/builtins/int/unegate.carbon
index 0bbd88372f7d..39bdaf6f153c 100644
--- a/toolchain/check/testdata/builtins/int/unegate.carbon
+++ b/toolchain/check/testdata/builtins/int/unegate.carbon
@@ -92,12 +92,13 @@ fn RuntimeCallIsValidTooMany(a: u32, b: u32, c: u32) -> u32 {
 }
 
 fn RuntimeCallIsValidBadReturnType(a: u32, b: u32) -> bool {
-  // CHECK:STDERR: fail_bad_decl.carbon:[[@LINE+6]]:10: error: 2 arguments passed to function expecting 1 argument [CallArgCountMismatch]
+  // CHECK:STDERR: fail_bad_decl.carbon:[[@LINE+7]]:10: error: 2 arguments passed to function expecting 1 argument [CallArgCountMismatch]
   // CHECK:STDERR:   return BadReturnType(a, b);
   // CHECK:STDERR:          ^~~~~~~~~~~~~~~~~~~
   // CHECK:STDERR: fail_bad_decl.carbon:[[@LINE-54]]:1: note: calling function declared here [InCallToEntity]
   // CHECK:STDERR: fn BadReturnType(a: u32) -> bool = "int.unegate";
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   return BadReturnType(a, b);
 }
 
diff --git a/toolchain/check/testdata/class/access_modifers.carbon b/toolchain/check/testdata/class/access_modifers.carbon
index 9262c203d7a0..556cc69c269d 100644
--- a/toolchain/check/testdata/class/access_modifers.carbon
+++ b/toolchain/check/testdata/class/access_modifers.carbon
@@ -128,12 +128,13 @@ class A {
 // CHECK:STDERR:                 ^
 // CHECK:STDERR:
 let x: i32 = A.x;
-// CHECK:STDERR: fail_global_access.carbon:[[@LINE+6]]:14: error: cannot access private member `y` of type `A` [ClassInvalidMemberAccess]
+// CHECK:STDERR: fail_global_access.carbon:[[@LINE+7]]:14: error: cannot access private member `y` of type `A` [ClassInvalidMemberAccess]
 // CHECK:STDERR: let y: i32 = A.y;
 // CHECK:STDERR:              ^~~
 // CHECK:STDERR: fail_global_access.carbon:[[@LINE-14]]:15: note: declared here [ClassMemberDeclaration]
 // CHECK:STDERR:   private let y: i32 = 5;
 // CHECK:STDERR:               ^
+// CHECK:STDERR:
 let y: i32 = A.y;
 
 // --- self_access.carbon
@@ -563,7 +564,7 @@ class A {
 // CHECK:STDOUT:   %A.ref.loc16: type = name_ref A, file.%A.decl [template = constants.%A]
 // CHECK:STDOUT:   %x.ref: <error> = name_ref x, <error> [template = <error>]
 // CHECK:STDOUT:   %x: %i32 = bind_name x, <error>
-// CHECK:STDOUT:   %A.ref.loc23: type = name_ref A, file.%A.decl [template = constants.%A]
+// CHECK:STDOUT:   %A.ref.loc24: type = name_ref A, file.%A.decl [template = constants.%A]
 // CHECK:STDOUT:   %y.ref: <error> = name_ref y, <error> [template = <error>]
 // CHECK:STDOUT:   %y: %i32 = bind_name y, <error>
 // CHECK:STDOUT:   return
diff --git a/toolchain/check/testdata/class/adapter/adapt.carbon b/toolchain/check/testdata/class/adapter/adapt.carbon
index a41cf449c9fb..1e3a2d9d368f 100644
--- a/toolchain/check/testdata/class/adapter/adapt.carbon
+++ b/toolchain/check/testdata/class/adapter/adapt.carbon
@@ -57,9 +57,10 @@ fn F() {
 }
 
 interface I {
-  // CHECK:STDERR: fail_misplaced.carbon:[[@LINE+3]]:3: error: `adapt` declaration outside class [ClassSpecificDeclOutsideClass]
+  // CHECK:STDERR: fail_misplaced.carbon:[[@LINE+4]]:3: error: `adapt` declaration outside class [ClassSpecificDeclOutsideClass]
   // CHECK:STDERR:   adapt i32;
   // CHECK:STDERR:   ^~~~~~~~~~
+  // CHECK:STDERR:
   adapt i32;
 }
 
diff --git a/toolchain/check/testdata/class/adapter/adapt_copy.carbon b/toolchain/check/testdata/class/adapter/adapt_copy.carbon
index 3e12949a7353..56dca0d13609 100644
--- a/toolchain/check/testdata/class/adapter/adapt_copy.carbon
+++ b/toolchain/check/testdata/class/adapter/adapt_copy.carbon
@@ -92,12 +92,13 @@ fn H(a: AdaptNoncopyableIndirect) -> AdaptNoncopyableIndirect {
   // CHECK:STDERR:                                     ^
   // CHECK:STDERR:
   var b: AdaptNoncopyableIndirect = a;
-  // CHECK:STDERR: fail_adapt_not_copyable_indirect.carbon:[[@LINE+6]]:3: error: cannot copy value of type `Noncopyable` [CopyOfUncopyableType]
+  // CHECK:STDERR: fail_adapt_not_copyable_indirect.carbon:[[@LINE+7]]:3: error: cannot copy value of type `Noncopyable` [CopyOfUncopyableType]
   // CHECK:STDERR:   return b;
   // CHECK:STDERR:   ^~~~~~~~~
-  // CHECK:STDERR: fail_adapt_not_copyable_indirect.carbon:[[@LINE+3]]:10: note: in copy of `AdaptNoncopyableIndirect` [InCopy]
+  // CHECK:STDERR: fail_adapt_not_copyable_indirect.carbon:[[@LINE+4]]:10: note: in copy of `AdaptNoncopyableIndirect` [InCopy]
   // CHECK:STDERR:   return b;
   // CHECK:STDERR:          ^
+  // CHECK:STDERR:
   return b;
 }
 
@@ -553,14 +554,14 @@ fn InTuple(c: (AdaptStruct, u32)) -> (AdaptStruct, u32) {
 // CHECK:STDOUT:   %tuple.elem1.loc20: %Noncopyable = tuple_access %.loc20_38.1, element1
 // CHECK:STDOUT:   assign %b.var, <error>
 // CHECK:STDOUT:   %b.ref: ref %AdaptNoncopyableIndirect = name_ref b, %b
-// CHECK:STDOUT:   %.loc27_11.1: ref %tuple.type.c9a = as_compatible %b.ref
-// CHECK:STDOUT:   %tuple.elem0.loc27_11.1: ref %i32 = tuple_access %.loc27_11.1, element0
-// CHECK:STDOUT:   %.loc27_11.2: %i32 = bind_value %tuple.elem0.loc27_11.1
-// CHECK:STDOUT:   %.loc27_11.3: ref %tuple.type.c9a = as_compatible %return
-// CHECK:STDOUT:   %tuple.elem0.loc27_11.2: ref %i32 = tuple_access %.loc27_11.3, element0
-// CHECK:STDOUT:   %.loc27_11.4: init %i32 = initialize_from %.loc27_11.2 to %tuple.elem0.loc27_11.2
-// CHECK:STDOUT:   %tuple.elem1.loc27: ref %Noncopyable = tuple_access %.loc27_11.1, element1
-// CHECK:STDOUT:   %.loc27_11.5: %Noncopyable = bind_value %tuple.elem1.loc27
+// CHECK:STDOUT:   %.loc28_11.1: ref %tuple.type.c9a = as_compatible %b.ref
+// CHECK:STDOUT:   %tuple.elem0.loc28_11.1: ref %i32 = tuple_access %.loc28_11.1, element0
+// CHECK:STDOUT:   %.loc28_11.2: %i32 = bind_value %tuple.elem0.loc28_11.1
+// CHECK:STDOUT:   %.loc28_11.3: ref %tuple.type.c9a = as_compatible %return
+// CHECK:STDOUT:   %tuple.elem0.loc28_11.2: ref %i32 = tuple_access %.loc28_11.3, element0
+// CHECK:STDOUT:   %.loc28_11.4: init %i32 = initialize_from %.loc28_11.2 to %tuple.elem0.loc28_11.2
+// CHECK:STDOUT:   %tuple.elem1.loc28: ref %Noncopyable = tuple_access %.loc28_11.1, element1
+// CHECK:STDOUT:   %.loc28_11.5: %Noncopyable = bind_value %tuple.elem1.loc28
 // CHECK:STDOUT:   return <error> to %return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/adapter/extend_adapt.carbon b/toolchain/check/testdata/class/adapter/extend_adapt.carbon
index fd07bc9fbf4a..9c16184fe40d 100644
--- a/toolchain/check/testdata/class/adapter/extend_adapt.carbon
+++ b/toolchain/check/testdata/class/adapter/extend_adapt.carbon
@@ -131,9 +131,10 @@ class IntAdapter {
 
 fn F(a: IntAdapter) -> i32 {
   // Builtin types have no member names.
-  // CHECK:STDERR: fail_adapt_builtin.carbon:[[@LINE+3]]:10: error: member name `foo` not found in `IntAdapter` [MemberNameNotFoundInScope]
+  // CHECK:STDERR: fail_adapt_builtin.carbon:[[@LINE+4]]:10: error: member name `foo` not found in `IntAdapter` [MemberNameNotFoundInScope]
   // CHECK:STDERR:   return a.foo;
   // CHECK:STDERR:          ^~~~~
+  // CHECK:STDERR:
   return a.foo;
 }
 
diff --git a/toolchain/check/testdata/class/adapter/fail_adapt_bad_decl.carbon b/toolchain/check/testdata/class/adapter/fail_adapt_bad_decl.carbon
index a2c842ecb9b6..7509ed5e8131 100644
--- a/toolchain/check/testdata/class/adapter/fail_adapt_bad_decl.carbon
+++ b/toolchain/check/testdata/class/adapter/fail_adapt_bad_decl.carbon
@@ -95,9 +95,10 @@ interface I {
 
 class C {
   interface I {
-    // CHECK:STDERR: fail_bad_scope.carbon:[[@LINE+3]]:5: error: `adapt` declaration outside class [ClassSpecificDeclOutsideClass]
+    // CHECK:STDERR: fail_bad_scope.carbon:[[@LINE+4]]:5: error: `adapt` declaration outside class [ClassSpecificDeclOutsideClass]
     // CHECK:STDERR:     adapt {};
     // CHECK:STDERR:     ^~~~~~~~~
+    // CHECK:STDERR:
     adapt {};
   }
 }
@@ -290,7 +291,7 @@ class C {
 // CHECK:STDOUT:
 // CHECK:STDOUT: interface @I.2 {
 // CHECK:STDOUT:   %Self: %I.type.e30 = bind_symbolic_name Self, 0 [symbolic = constants.%Self.6ef]
-// CHECK:STDOUT:   %.loc23: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %.loc24: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:
 // CHECK:STDOUT: !members:
 // CHECK:STDOUT:   .Self = %Self
diff --git a/toolchain/check/testdata/class/adapter/fail_adapt_bad_type.carbon b/toolchain/check/testdata/class/adapter/fail_adapt_bad_type.carbon
index ebef84227ef3..f9cf1987285f 100644
--- a/toolchain/check/testdata/class/adapter/fail_adapt_bad_type.carbon
+++ b/toolchain/check/testdata/class/adapter/fail_adapt_bad_type.carbon
@@ -15,12 +15,13 @@ library "[[@TEST_NAME]]";
 class Incomplete;
 
 class AdaptIncomplete {
-  // CHECK:STDERR: fail_incomplete_type.carbon:[[@LINE+6]]:3: error: adapted type `Incomplete` is an incomplete type [IncompleteTypeInAdaptDecl]
+  // CHECK:STDERR: fail_incomplete_type.carbon:[[@LINE+7]]:3: error: adapted type `Incomplete` is an incomplete type [IncompleteTypeInAdaptDecl]
   // CHECK:STDERR:   adapt Incomplete;
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~
   // CHECK:STDERR: fail_incomplete_type.carbon:[[@LINE-6]]:1: note: class was forward declared here [ClassForwardDeclaredHere]
   // CHECK:STDERR: class Incomplete;
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   adapt Incomplete;
 }
 
diff --git a/toolchain/check/testdata/class/adapter/fail_adapt_modifiers.carbon b/toolchain/check/testdata/class/adapter/fail_adapt_modifiers.carbon
index 1bbea007eb1b..95249c47e766 100644
--- a/toolchain/check/testdata/class/adapter/fail_adapt_modifiers.carbon
+++ b/toolchain/check/testdata/class/adapter/fail_adapt_modifiers.carbon
@@ -46,12 +46,13 @@ class C4 {
 }
 
 class C5 {
-  // CHECK:STDERR: fail_adapt_modifiers.carbon:[[@LINE+6]]:10: error: `base` not allowed on declaration with `extend` [ModifierNotAllowedWith]
+  // CHECK:STDERR: fail_adapt_modifiers.carbon:[[@LINE+7]]:10: error: `base` not allowed on declaration with `extend` [ModifierNotAllowedWith]
   // CHECK:STDERR:   extend base adapt B;
   // CHECK:STDERR:          ^~~~
-  // CHECK:STDERR: fail_adapt_modifiers.carbon:[[@LINE+3]]:3: note: `extend` previously appeared here [ModifierPrevious]
+  // CHECK:STDERR: fail_adapt_modifiers.carbon:[[@LINE+4]]:3: note: `extend` previously appeared here [ModifierPrevious]
   // CHECK:STDERR:   extend base adapt B;
   // CHECK:STDERR:   ^~~~~~
+  // CHECK:STDERR:
   extend base adapt B;
 }
 
diff --git a/toolchain/check/testdata/class/adapter/fail_adapt_with_base.carbon b/toolchain/check/testdata/class/adapter/fail_adapt_with_base.carbon
index 93cba32d799e..b23599769480 100644
--- a/toolchain/check/testdata/class/adapter/fail_adapt_with_base.carbon
+++ b/toolchain/check/testdata/class/adapter/fail_adapt_with_base.carbon
@@ -10,12 +10,13 @@
 class Simple {};
 base class AdaptWithVirtual {
   virtual fn F();
-  // CHECK:STDERR: fail_adapt_with_base.carbon:[[@LINE+6]]:3: error: adapter with virtual function [AdaptWithVirtual]
+  // CHECK:STDERR: fail_adapt_with_base.carbon:[[@LINE+7]]:3: error: adapter with virtual function [AdaptWithVirtual]
   // CHECK:STDERR:   adapt Simple;
   // CHECK:STDERR:   ^~~~~~~~~~~~~
   // CHECK:STDERR: fail_adapt_with_base.carbon:[[@LINE-4]]:3: note: first virtual function declaration is here [AdaptWithVirtualHere]
   // CHECK:STDERR:   virtual fn F();
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   adapt Simple;
 }
 
diff --git a/toolchain/check/testdata/class/adapter/fail_adapt_with_subobjects.carbon b/toolchain/check/testdata/class/adapter/fail_adapt_with_subobjects.carbon
index a4ce0134f490..06d5edc415a5 100644
--- a/toolchain/check/testdata/class/adapter/fail_adapt_with_subobjects.carbon
+++ b/toolchain/check/testdata/class/adapter/fail_adapt_with_subobjects.carbon
@@ -65,12 +65,13 @@ base class Base {}
 class AdaptWithBaseAndFields {
   extend base: Base;
   var n: i32;
-  // CHECK:STDERR: fail_adapt_with_base_and_fields.carbon:[[@LINE+6]]:3: error: adapter with base class [AdaptWithBase]
+  // CHECK:STDERR: fail_adapt_with_base_and_fields.carbon:[[@LINE+7]]:3: error: adapter with base class [AdaptWithBase]
   // CHECK:STDERR:   adapt {};
   // CHECK:STDERR:   ^~~~~~~~~
   // CHECK:STDERR: fail_adapt_with_base_and_fields.carbon:[[@LINE-5]]:3: note: `base` declaration is here [AdaptWithBaseHere]
   // CHECK:STDERR:   extend base: Base;
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   adapt {};
 }
 
@@ -208,9 +209,9 @@ class AdaptWithBaseAndFields {
 // CHECK:STDOUT:   %Base.ref: type = name_ref Base, file.%Base.decl [template = constants.%Base]
 // CHECK:STDOUT:   %.loc7: %AdaptWithBaseAndFields.elem.767 = base_decl %Base.ref, element<invalid> [template]
 // CHECK:STDOUT:   %.loc8: %AdaptWithBaseAndFields.elem.ddf = field_decl n, element<invalid> [template]
-// CHECK:STDOUT:   %.loc15_10: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:   %.loc15_11: type = converted %.loc15_10, constants.%empty_struct_type [template = constants.%empty_struct_type]
-// CHECK:STDOUT:   adapt_decl %.loc15_11 [template]
+// CHECK:STDOUT:   %.loc16_10: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %.loc16_11: type = converted %.loc16_10, constants.%empty_struct_type [template = constants.%empty_struct_type]
+// CHECK:STDOUT:   adapt_decl %.loc16_11 [template]
 // CHECK:STDOUT:   complete_type_witness = <error>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/adapter/init_adapt.carbon b/toolchain/check/testdata/class/adapter/init_adapt.carbon
index b124a77ecb9e..4d8dca3e220d 100644
--- a/toolchain/check/testdata/class/adapter/init_adapt.carbon
+++ b/toolchain/check/testdata/class/adapter/init_adapt.carbon
@@ -83,12 +83,13 @@ fn MakeAdaptC() -> AdaptC;
 // CHECK:STDERR:
 var d: AdaptC = MakeC();
 
-// CHECK:STDERR: fail_not_implicit.carbon:[[@LINE+6]]:1: error: cannot implicitly convert from `AdaptC` to `C` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_not_implicit.carbon:[[@LINE+7]]:1: error: cannot implicitly convert from `AdaptC` to `C` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var e: C = MakeAdaptC();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_not_implicit.carbon:[[@LINE+3]]:1: note: type `AdaptC` does not implement interface `Core.ImplicitAs(C)` [MissingImplInMemberAccessNote]
+// CHECK:STDERR: fail_not_implicit.carbon:[[@LINE+4]]:1: note: type `AdaptC` does not implement interface `Core.ImplicitAs(C)` [MissingImplInMemberAccessNote]
 // CHECK:STDERR: var e: C = MakeAdaptC();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 var e: C = MakeAdaptC();
 
 // CHECK:STDOUT: --- init_adapt.carbon
@@ -370,9 +371,9 @@ var e: C = MakeAdaptC();
 // CHECK:STDOUT:   %.loc46_24: %AdaptC = converted %MakeC.call, <error> [template = <error>]
 // CHECK:STDOUT:   assign file.%d.var, <error>
 // CHECK:STDOUT:   %MakeAdaptC.ref: %MakeAdaptC.type = name_ref MakeAdaptC, file.%MakeAdaptC.decl [template = constants.%MakeAdaptC]
-// CHECK:STDOUT:   %.loc54_23: ref %AdaptC = temporary_storage
-// CHECK:STDOUT:   %MakeAdaptC.call: init %AdaptC = call %MakeAdaptC.ref() to %.loc54_23
-// CHECK:STDOUT:   %.loc54_24: %C = converted %MakeAdaptC.call, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc55_23: ref %AdaptC = temporary_storage
+// CHECK:STDOUT:   %MakeAdaptC.call: init %AdaptC = call %MakeAdaptC.ref() to %.loc55_23
+// CHECK:STDOUT:   %.loc55_24: %C = converted %MakeAdaptC.call, <error> [template = <error>]
 // CHECK:STDOUT:   assign file.%e.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/class/base.carbon b/toolchain/check/testdata/class/base.carbon
index 3caebc0e8cd0..5abff4b389d3 100644
--- a/toolchain/check/testdata/class/base.carbon
+++ b/toolchain/check/testdata/class/base.carbon
@@ -38,9 +38,10 @@ base class Base {
 class Derived {
   var d: i32;
 
-  // CHECK:STDERR: fail_base_after_field.carbon:[[@LINE+3]]:3: error: `base` declaration must appear before field declarations [BaseDeclAfterFieldDecl]
+  // CHECK:STDERR: fail_base_after_field.carbon:[[@LINE+4]]:3: error: `base` declaration must appear before field declarations [BaseDeclAfterFieldDecl]
   // CHECK:STDERR:   extend base: Base;
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   extend base: Base;
 }
 
diff --git a/toolchain/check/testdata/class/cross_package_import.carbon b/toolchain/check/testdata/class/cross_package_import.carbon
index 4374eca8ceac..6dcef1f2b8d6 100644
--- a/toolchain/check/testdata/class/cross_package_import.carbon
+++ b/toolchain/check/testdata/class/cross_package_import.carbon
@@ -94,9 +94,10 @@ library "[[@TEST_NAME]]";
 import Other library "other_define";
 import Other library "other_conflict";
 
-// CHECK:STDERR: fail_conflict.carbon:[[@LINE+3]]:8: note: in name lookup for `C` [InNameLookup]
+// CHECK:STDERR: fail_conflict.carbon:[[@LINE+4]]:8: note: in name lookup for `C` [InNameLookup]
 // CHECK:STDERR: var c: Other.C = {};
 // CHECK:STDERR:        ^~~~~~~
+// CHECK:STDERR:
 var c: Other.C = {};
 
 // CHECK:STDOUT: --- other_define.carbon
@@ -351,10 +352,10 @@ var c: Other.C = {};
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %.loc18_19.1: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:   %.loc18_19.2: init %C = class_init (), file.%c.var [template = constants.%C.val]
-// CHECK:STDOUT:   %.loc18_20: init %C = converted %.loc18_19.1, %.loc18_19.2 [template = constants.%C.val]
-// CHECK:STDOUT:   assign file.%c.var, %.loc18_20
+// CHECK:STDOUT:   %.loc19_19.1: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %.loc19_19.2: init %C = class_init (), file.%c.var [template = constants.%C.val]
+// CHECK:STDOUT:   %.loc19_20: init %C = converted %.loc19_19.1, %.loc19_19.2 [template = constants.%C.val]
+// CHECK:STDOUT:   assign file.%c.var, %.loc19_20
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/fail_abstract.carbon b/toolchain/check/testdata/class/fail_abstract.carbon
index e3ed943960cc..81fa095f5006 100644
--- a/toolchain/check/testdata/class/fail_abstract.carbon
+++ b/toolchain/check/testdata/class/fail_abstract.carbon
@@ -176,7 +176,7 @@ abstract class Abstract {
 fn ReturnAbstract() -> Abstract;
 
 fn CallReturnAbstract() {
-  // CHECK:STDERR: fail_call_abstract_return.carbon:[[@LINE+9]]:3: error: function returns abstract type `Abstract` [AbstractTypeInFunctionReturnType]
+  // CHECK:STDERR: fail_call_abstract_return.carbon:[[@LINE+10]]:3: error: function returns abstract type `Abstract` [AbstractTypeInFunctionReturnType]
   // CHECK:STDERR:   ReturnAbstract();
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~
   // CHECK:STDERR: fail_call_abstract_return.carbon:[[@LINE-9]]:1: note: class was declared abstract here [ClassAbstractHere]
@@ -185,6 +185,7 @@ fn CallReturnAbstract() {
   // CHECK:STDERR: fail_call_abstract_return.carbon:[[@LINE-9]]:21: note: return type declared here [IncompleteReturnTypeHere]
   // CHECK:STDERR: fn ReturnAbstract() -> Abstract;
   // CHECK:STDERR:                     ^~~~~~~~~~~
+  // CHECK:STDERR:
   ReturnAbstract();
 }
 
diff --git a/toolchain/check/testdata/class/fail_addr_not_self.carbon b/toolchain/check/testdata/class/fail_addr_not_self.carbon
index 085c34d6918d..d2e0e6542428 100644
--- a/toolchain/check/testdata/class/fail_addr_not_self.carbon
+++ b/toolchain/check/testdata/class/fail_addr_not_self.carbon
@@ -15,9 +15,10 @@ class Class {
   // CHECK:STDERR:
   fn F[addr a:! Class*]();
 
-  // CHECK:STDERR: fail_addr_not_self.carbon:[[@LINE+3]]:8: error: `addr` can only be applied to a `self` parameter [AddrOnNonSelfParam]
+  // CHECK:STDERR: fail_addr_not_self.carbon:[[@LINE+4]]:8: error: `addr` can only be applied to a `self` parameter [AddrOnNonSelfParam]
   // CHECK:STDERR:   fn G(addr b: Class*);
   // CHECK:STDERR:        ^~~~
+  // CHECK:STDERR:
   fn G(addr b: Class*);
 }
 
@@ -69,7 +70,7 @@ class Class {
 // CHECK:STDOUT:     %b.param_patt: %ptr = value_param_pattern %b.patt, runtime_param0
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %b.param: %ptr = value_param runtime_param0
-// CHECK:STDOUT:     %.loc21: type = splice_block %ptr [template = constants.%ptr] {
+// CHECK:STDOUT:     %.loc22: type = splice_block %ptr [template = constants.%ptr] {
 // CHECK:STDOUT:       %Class.ref: type = name_ref Class, file.%Class.decl [template = constants.%Class]
 // CHECK:STDOUT:       %ptr: type = ptr_type %Class [template = constants.%ptr]
 // CHECK:STDOUT:     }
diff --git a/toolchain/check/testdata/class/fail_addr_self.carbon b/toolchain/check/testdata/class/fail_addr_self.carbon
index f2e8004fe2d4..961da001c456 100644
--- a/toolchain/check/testdata/class/fail_addr_self.carbon
+++ b/toolchain/check/testdata/class/fail_addr_self.carbon
@@ -18,12 +18,13 @@ class Class {
 }
 
 fn F(c: Class, p: Class*) {
-  // CHECK:STDERR: fail_addr_self.carbon:[[@LINE+6]]:3: error: `addr self` method cannot be invoked on a value [AddrSelfIsNonRef]
+  // CHECK:STDERR: fail_addr_self.carbon:[[@LINE+7]]:3: error: `addr self` method cannot be invoked on a value [AddrSelfIsNonRef]
   // CHECK:STDERR:   c.F();
   // CHECK:STDERR:   ^
   // CHECK:STDERR: fail_addr_self.carbon:[[@LINE-12]]:8: note: initializing function parameter [InCallToFunctionParam]
   // CHECK:STDERR:   fn F[addr self: Class*]();
   // CHECK:STDERR:        ^~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   c.F();
 
   c.G();
@@ -114,26 +115,26 @@ fn F(c: Class, p: Class*) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @F.2(%c.param_patt: %Class, %p.param_patt: %ptr.e71) {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %c.ref.loc27: %Class = name_ref c, %c
-// CHECK:STDOUT:   %F.ref.loc27: %F.type.f1b = name_ref F, @Class.%F.decl [template = constants.%F.1f2]
-// CHECK:STDOUT:   %F.bound.loc27: <bound method> = bound_method %c.ref.loc27, %F.ref.loc27
-// CHECK:STDOUT:   %F.call.loc27: init %empty_tuple.type = call %F.bound.loc27(<error>)
-// CHECK:STDOUT:   %c.ref.loc29: %Class = name_ref c, %c
-// CHECK:STDOUT:   %G.ref.loc29: %G.type = name_ref G, @Class.%G.decl [template = constants.%G]
-// CHECK:STDOUT:   %G.bound.loc29: <bound method> = bound_method %c.ref.loc29, %G.ref.loc29
-// CHECK:STDOUT:   %G.call.loc29: init %empty_tuple.type = call %G.bound.loc29(%c.ref.loc29)
-// CHECK:STDOUT:   %p.ref.loc32: %ptr.e71 = name_ref p, %p
-// CHECK:STDOUT:   %.loc32: ref %Class = deref %p.ref.loc32
-// CHECK:STDOUT:   %F.ref.loc32: %F.type.f1b = name_ref F, @Class.%F.decl [template = constants.%F.1f2]
-// CHECK:STDOUT:   %F.bound.loc32: <bound method> = bound_method %.loc32, %F.ref.loc32
-// CHECK:STDOUT:   %addr: %ptr.e71 = addr_of %.loc32
-// CHECK:STDOUT:   %F.call.loc32: init %empty_tuple.type = call %F.bound.loc32(%addr)
-// CHECK:STDOUT:   %p.ref.loc34: %ptr.e71 = name_ref p, %p
-// CHECK:STDOUT:   %.loc34_4.1: ref %Class = deref %p.ref.loc34
-// CHECK:STDOUT:   %G.ref.loc34: %G.type = name_ref G, @Class.%G.decl [template = constants.%G]
-// CHECK:STDOUT:   %G.bound.loc34: <bound method> = bound_method %.loc34_4.1, %G.ref.loc34
-// CHECK:STDOUT:   %.loc34_4.2: %Class = bind_value %.loc34_4.1
-// CHECK:STDOUT:   %G.call.loc34: init %empty_tuple.type = call %G.bound.loc34(%.loc34_4.2)
+// CHECK:STDOUT:   %c.ref.loc28: %Class = name_ref c, %c
+// CHECK:STDOUT:   %F.ref.loc28: %F.type.f1b = name_ref F, @Class.%F.decl [template = constants.%F.1f2]
+// CHECK:STDOUT:   %F.bound.loc28: <bound method> = bound_method %c.ref.loc28, %F.ref.loc28
+// CHECK:STDOUT:   %F.call.loc28: init %empty_tuple.type = call %F.bound.loc28(<error>)
+// CHECK:STDOUT:   %c.ref.loc30: %Class = name_ref c, %c
+// CHECK:STDOUT:   %G.ref.loc30: %G.type = name_ref G, @Class.%G.decl [template = constants.%G]
+// CHECK:STDOUT:   %G.bound.loc30: <bound method> = bound_method %c.ref.loc30, %G.ref.loc30
+// CHECK:STDOUT:   %G.call.loc30: init %empty_tuple.type = call %G.bound.loc30(%c.ref.loc30)
+// CHECK:STDOUT:   %p.ref.loc33: %ptr.e71 = name_ref p, %p
+// CHECK:STDOUT:   %.loc33: ref %Class = deref %p.ref.loc33
+// CHECK:STDOUT:   %F.ref.loc33: %F.type.f1b = name_ref F, @Class.%F.decl [template = constants.%F.1f2]
+// CHECK:STDOUT:   %F.bound.loc33: <bound method> = bound_method %.loc33, %F.ref.loc33
+// CHECK:STDOUT:   %addr: %ptr.e71 = addr_of %.loc33
+// CHECK:STDOUT:   %F.call.loc33: init %empty_tuple.type = call %F.bound.loc33(%addr)
+// CHECK:STDOUT:   %p.ref.loc35: %ptr.e71 = name_ref p, %p
+// CHECK:STDOUT:   %.loc35_4.1: ref %Class = deref %p.ref.loc35
+// CHECK:STDOUT:   %G.ref.loc35: %G.type = name_ref G, @Class.%G.decl [template = constants.%G]
+// CHECK:STDOUT:   %G.bound.loc35: <bound method> = bound_method %.loc35_4.1, %G.ref.loc35
+// CHECK:STDOUT:   %.loc35_4.2: %Class = bind_value %.loc35_4.1
+// CHECK:STDOUT:   %G.call.loc35: init %empty_tuple.type = call %G.bound.loc35(%.loc35_4.2)
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/fail_base_as_declared_name.carbon b/toolchain/check/testdata/class/fail_base_as_declared_name.carbon
index 59dc0914996c..defd44bc36f4 100644
--- a/toolchain/check/testdata/class/fail_base_as_declared_name.carbon
+++ b/toolchain/check/testdata/class/fail_base_as_declared_name.carbon
@@ -10,13 +10,14 @@
 
 namespace N;
 
-// CHECK:STDERR: fail_base_as_declared_name.carbon:[[@LINE+7]]:6: error: `.` should be followed by a name [ExpectedDeclNameAfterPeriod]
+// CHECK:STDERR: fail_base_as_declared_name.carbon:[[@LINE+8]]:6: error: `.` should be followed by a name [ExpectedDeclNameAfterPeriod]
 // CHECK:STDERR: fn N.base() {}
 // CHECK:STDERR:      ^~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_base_as_declared_name.carbon:[[@LINE+3]]:6: error: semantics TODO: `handle invalid parse trees in `check`` [SemanticsTodo]
+// CHECK:STDERR: fail_base_as_declared_name.carbon:[[@LINE+4]]:6: error: semantics TODO: `handle invalid parse trees in `check`` [SemanticsTodo]
 // CHECK:STDERR: fn N.base() {}
 // CHECK:STDERR:      ^~~~
+// CHECK:STDERR:
 fn N.base() {}
 
 // CHECK:STDOUT: --- fail_base_as_declared_name.carbon
diff --git a/toolchain/check/testdata/class/fail_base_bad_type.carbon b/toolchain/check/testdata/class/fail_base_bad_type.carbon
index 2694236f36fe..2d768ab66ca5 100644
--- a/toolchain/check/testdata/class/fail_base_bad_type.carbon
+++ b/toolchain/check/testdata/class/fail_base_bad_type.carbon
@@ -171,9 +171,10 @@ fn AccessMemberWithInvalidBaseFinal_WithMember(p: DeriveFromFinal*) -> i32 {
 }
 
 fn AccessMemberWithInvalidBaseFinal_NoMember(p: DeriveFromFinal*) -> i32 {
-  // CHECK:STDERR: fail_derive_from_final.carbon:[[@LINE+3]]:10: error: member name `b` not found in `DeriveFromFinal` [MemberNameNotFoundInScope]
+  // CHECK:STDERR: fail_derive_from_final.carbon:[[@LINE+4]]:10: error: member name `b` not found in `DeriveFromFinal` [MemberNameNotFoundInScope]
   // CHECK:STDERR:   return (*p).b;
   // CHECK:STDERR:          ^~~~~~
+  // CHECK:STDERR:
   return (*p).b;
 }
 
@@ -832,7 +833,7 @@ fn AccessMemberWithInvalidBaseFinal_NoMember(p: DeriveFromFinal*) -> i32 {
 // CHECK:STDOUT: fn @AccessMemberWithInvalidBaseFinal_NoMember(%p.param_patt: %ptr.160) -> %i32 {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %p.ref: %ptr.160 = name_ref p, %p
-// CHECK:STDOUT:   %.loc29: ref %DeriveFromFinal = deref %p.ref
+// CHECK:STDOUT:   %.loc30: ref %DeriveFromFinal = deref %p.ref
 // CHECK:STDOUT:   %b.ref: <error> = name_ref b, <error> [template = <error>]
 // CHECK:STDOUT:   return <error>
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/class/fail_base_method_define.carbon b/toolchain/check/testdata/class/fail_base_method_define.carbon
index 934be98deafb..b5e99ce5f535 100644
--- a/toolchain/check/testdata/class/fail_base_method_define.carbon
+++ b/toolchain/check/testdata/class/fail_base_method_define.carbon
@@ -26,9 +26,10 @@ class D {
 // CHECK:STDERR:
 fn D.F() {}
 
-// CHECK:STDERR: fail_base_method_define.carbon:[[@LINE+3]]:6: error: name `C` not found [NameNotFound]
+// CHECK:STDERR: fail_base_method_define.carbon:[[@LINE+4]]:6: error: name `C` not found [NameNotFound]
 // CHECK:STDERR: fn D.C.F() {}
 // CHECK:STDERR:      ^
+// CHECK:STDERR:
 fn D.C.F() {}
 
 // CHECK:STDOUT: --- fail_base_method_define.carbon
diff --git a/toolchain/check/testdata/class/fail_base_misplaced.carbon b/toolchain/check/testdata/class/fail_base_misplaced.carbon
index b8af0720c8d9..ece0ddd9258d 100644
--- a/toolchain/check/testdata/class/fail_base_misplaced.carbon
+++ b/toolchain/check/testdata/class/fail_base_misplaced.carbon
@@ -26,9 +26,10 @@ fn F() {
 
 class C {
   fn F() {
-    // CHECK:STDERR: fail_base_misplaced.carbon:[[@LINE+3]]:5: error: `base` declaration outside class [ClassSpecificDeclOutsideClass]
+    // CHECK:STDERR: fail_base_misplaced.carbon:[[@LINE+4]]:5: error: `base` declaration outside class [ClassSpecificDeclOutsideClass]
     // CHECK:STDERR:     extend base: B;
     // CHECK:STDERR:     ^~~~~~~~~~~~~~~
+    // CHECK:STDERR:
     extend base: B;
   }
 }
diff --git a/toolchain/check/testdata/class/fail_base_modifiers.carbon b/toolchain/check/testdata/class/fail_base_modifiers.carbon
index 6a1ea9f272b2..fbefcaa34734 100644
--- a/toolchain/check/testdata/class/fail_base_modifiers.carbon
+++ b/toolchain/check/testdata/class/fail_base_modifiers.carbon
@@ -42,12 +42,13 @@ class C3 {
 }
 
 class C4 {
-  // CHECK:STDERR: fail_base_modifiers.carbon:[[@LINE+6]]:10: error: `extend` repeated on declaration [ModifierRepeated]
+  // CHECK:STDERR: fail_base_modifiers.carbon:[[@LINE+7]]:10: error: `extend` repeated on declaration [ModifierRepeated]
   // CHECK:STDERR:   extend extend base: B;
   // CHECK:STDERR:          ^~~~~~
-  // CHECK:STDERR: fail_base_modifiers.carbon:[[@LINE+3]]:3: note: `extend` previously appeared here [ModifierPrevious]
+  // CHECK:STDERR: fail_base_modifiers.carbon:[[@LINE+4]]:3: note: `extend` previously appeared here [ModifierPrevious]
   // CHECK:STDERR:   extend extend base: B;
   // CHECK:STDERR:   ^~~~~~
+  // CHECK:STDERR:
   extend extend base: B;
 }
 
@@ -121,7 +122,7 @@ class C4 {
 // CHECK:STDOUT:
 // CHECK:STDOUT: class @C4 {
 // CHECK:STDOUT:   %B.ref: type = name_ref B, file.%B.decl [template = constants.%B]
-// CHECK:STDOUT:   %.loc51: %C4.elem = base_decl %B.ref, element0 [template]
+// CHECK:STDOUT:   %.loc52: %C4.elem = base_decl %B.ref, element0 [template]
 // CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %struct_type.base [template = constants.%complete_type.98e]
 // CHECK:STDOUT:   complete_type_witness = %complete_type
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/class/fail_base_no_extend.carbon b/toolchain/check/testdata/class/fail_base_no_extend.carbon
index 20099c79b1f5..0e37dddaeac5 100644
--- a/toolchain/check/testdata/class/fail_base_no_extend.carbon
+++ b/toolchain/check/testdata/class/fail_base_no_extend.carbon
@@ -11,9 +11,10 @@
 base class B {}
 
 class C {
-  // CHECK:STDERR: fail_base_no_extend.carbon:[[@LINE+3]]:3: error: missing `extend` before `base` declaration [BaseMissingExtend]
+  // CHECK:STDERR: fail_base_no_extend.carbon:[[@LINE+4]]:3: error: missing `extend` before `base` declaration [BaseMissingExtend]
   // CHECK:STDERR:   base: B;
   // CHECK:STDERR:   ^~~~~~~~
+  // CHECK:STDERR:
   base: B;
 }
 
@@ -54,7 +55,7 @@ class C {
 // CHECK:STDOUT:
 // CHECK:STDOUT: class @C {
 // CHECK:STDOUT:   %B.ref: type = name_ref B, file.%B.decl [template = constants.%B]
-// CHECK:STDOUT:   %.loc17: %C.elem = base_decl %B.ref, element0 [template]
+// CHECK:STDOUT:   %.loc18: %C.elem = base_decl %B.ref, element0 [template]
 // CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %struct_type.base [template = constants.%complete_type.98e]
 // CHECK:STDOUT:   complete_type_witness = %complete_type
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/class/fail_base_repeated.carbon b/toolchain/check/testdata/class/fail_base_repeated.carbon
index 5b0c5a09aff9..01082b1cef26 100644
--- a/toolchain/check/testdata/class/fail_base_repeated.carbon
+++ b/toolchain/check/testdata/class/fail_base_repeated.carbon
@@ -26,12 +26,13 @@ class C {
 class D {
   // TODO: Consider adding a custom diagnostic for this case.
   extend base: B1;
-  // CHECK:STDERR: fail_base_repeated.carbon:[[@LINE+6]]:3: error: multiple `base` declarations in class; multiple inheritance is not permitted [BaseDeclRepeated]
+  // CHECK:STDERR: fail_base_repeated.carbon:[[@LINE+7]]:3: error: multiple `base` declarations in class; multiple inheritance is not permitted [BaseDeclRepeated]
   // CHECK:STDERR:   extend base: B1;
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~
   // CHECK:STDERR: fail_base_repeated.carbon:[[@LINE-4]]:3: note: previous `base` declaration is here [ClassSpecificDeclPrevious]
   // CHECK:STDERR:   extend base: B1;
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   extend base: B1;
 }
 
@@ -93,7 +94,7 @@ class D {
 // CHECK:STDOUT: class @D {
 // CHECK:STDOUT:   %B1.ref.loc28: type = name_ref B1, file.%B1.decl [template = constants.%B1]
 // CHECK:STDOUT:   %.loc28: %D.elem = base_decl %B1.ref.loc28, element0 [template]
-// CHECK:STDOUT:   %B1.ref.loc35: type = name_ref B1, file.%B1.decl [template = constants.%B1]
+// CHECK:STDOUT:   %B1.ref.loc36: type = name_ref B1, file.%B1.decl [template = constants.%B1]
 // CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %struct_type.base [template = constants.%complete_type.5ac]
 // CHECK:STDOUT:   complete_type_witness = %complete_type
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/class/fail_base_unbound.carbon b/toolchain/check/testdata/class/fail_base_unbound.carbon
index c4aa0ac89a57..5c714270d034 100644
--- a/toolchain/check/testdata/class/fail_base_unbound.carbon
+++ b/toolchain/check/testdata/class/fail_base_unbound.carbon
@@ -14,9 +14,10 @@ class C {
   extend base: B;
 }
 
-// CHECK:STDERR: fail_base_unbound.carbon:[[@LINE+3]]:12: error: expression cannot be used as a value [UseOfNonExprAsValue]
+// CHECK:STDERR: fail_base_unbound.carbon:[[@LINE+4]]:12: error: expression cannot be used as a value [UseOfNonExprAsValue]
 // CHECK:STDERR: let b: B = C.base;
 // CHECK:STDERR:            ^~~~~~
+// CHECK:STDERR:
 let b: B = C.base;
 
 // CHECK:STDOUT: --- fail_base_unbound.carbon
diff --git a/toolchain/check/testdata/class/fail_compound_type_mismatch.carbon b/toolchain/check/testdata/class/fail_compound_type_mismatch.carbon
index 94beaf8a5389..453fc7ce4fe5 100644
--- a/toolchain/check/testdata/class/fail_compound_type_mismatch.carbon
+++ b/toolchain/check/testdata/class/fail_compound_type_mismatch.carbon
@@ -17,12 +17,13 @@ class B {
 }
 
 fn AccessBInA(a: A) -> i32 {
-  // CHECK:STDERR: fail_compound_type_mismatch.carbon:[[@LINE+6]]:10: error: cannot implicitly convert from `A` to `B` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_compound_type_mismatch.carbon:[[@LINE+7]]:10: error: cannot implicitly convert from `A` to `B` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   return a.(B.b);
   // CHECK:STDERR:          ^~~~~~~
-  // CHECK:STDERR: fail_compound_type_mismatch.carbon:[[@LINE+3]]:10: note: type `A` does not implement interface `Core.ImplicitAs(B)` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR: fail_compound_type_mismatch.carbon:[[@LINE+4]]:10: note: type `A` does not implement interface `Core.ImplicitAs(B)` [MissingImplInMemberAccessNote]
   // CHECK:STDERR:   return a.(B.b);
   // CHECK:STDERR:          ^~~~~~~
+  // CHECK:STDERR:
   return a.(B.b);
 }
 
@@ -95,8 +96,8 @@ fn AccessBInA(a: A) -> i32 {
 // CHECK:STDOUT:   %a.ref: %A = name_ref a, %a
 // CHECK:STDOUT:   %B.ref: type = name_ref B, file.%B.decl [template = constants.%B]
 // CHECK:STDOUT:   %b.ref: %B.elem = name_ref b, @B.%.loc16 [template = @B.%.loc16]
-// CHECK:STDOUT:   %.loc26_11.1: %B = converted %a.ref, <error> [template = <error>]
-// CHECK:STDOUT:   %.loc26_11.2: %i32 = class_element_access <error>, element0 [template = <error>]
+// CHECK:STDOUT:   %.loc27_11.1: %B = converted %a.ref, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc27_11.2: %i32 = class_element_access <error>, element0 [template = <error>]
 // CHECK:STDOUT:   return <error>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/fail_convert_to_invalid.carbon b/toolchain/check/testdata/class/fail_convert_to_invalid.carbon
index 1dfafb29e442..c3c8b763ff43 100644
--- a/toolchain/check/testdata/class/fail_convert_to_invalid.carbon
+++ b/toolchain/check/testdata/class/fail_convert_to_invalid.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/fail_convert_to_invalid.carbon
 
 class C {
-  // CHECK:STDERR: fail_convert_to_invalid.carbon:[[@LINE+3]]:10: error: name `NoSuchType` not found [NameNotFound]
+  // CHECK:STDERR: fail_convert_to_invalid.carbon:[[@LINE+4]]:10: error: name `NoSuchType` not found [NameNotFound]
   // CHECK:STDERR:   var a: NoSuchType;
   // CHECK:STDERR:          ^~~~~~~~~~
+  // CHECK:STDERR:
   var a: NoSuchType;
 }
 
@@ -55,7 +56,7 @@ fn Make() -> C {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: class @C {
-// CHECK:STDOUT:   %.loc15: <error> = field_decl a, element0 [template]
+// CHECK:STDOUT:   %.loc16: <error> = field_decl a, element0 [template]
 // CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness <error> [template = <error>]
 // CHECK:STDOUT:   complete_type_witness = %complete_type
 // CHECK:STDOUT: }
@@ -63,7 +64,7 @@ fn Make() -> C {
 // CHECK:STDOUT: fn @Make() -> %return.param_patt: %C {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %int_123: Core.IntLiteral = int_value 123 [template = constants.%int_123]
-// CHECK:STDOUT:   %.loc19: %struct_type.a = struct_literal (%int_123)
+// CHECK:STDOUT:   %.loc20: %struct_type.a = struct_literal (%int_123)
 // CHECK:STDOUT:   return <error> to %return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/fail_derived_to_base.carbon b/toolchain/check/testdata/class/fail_derived_to_base.carbon
index 07f6f0db36dd..dfb9ccd9c9f7 100644
--- a/toolchain/check/testdata/class/fail_derived_to_base.carbon
+++ b/toolchain/check/testdata/class/fail_derived_to_base.carbon
@@ -32,12 +32,13 @@ fn ConvertUnrelated(p: B2*) -> A1* { return p; }
 
 class Incomplete;
 
-// CHECK:STDERR: fail_derived_to_base.carbon:[[@LINE+6]]:47: error: cannot implicitly convert from `Incomplete*` to `A2*` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_derived_to_base.carbon:[[@LINE+7]]:47: error: cannot implicitly convert from `Incomplete*` to `A2*` [ImplicitAsConversionFailure]
 // CHECK:STDERR: fn ConvertIncomplete(p: Incomplete*) -> A2* { return p; }
 // CHECK:STDERR:                                               ^~~~~~~~~
-// CHECK:STDERR: fail_derived_to_base.carbon:[[@LINE+3]]:47: note: type `Incomplete*` does not implement interface `Core.ImplicitAs(A2*)` [MissingImplInMemberAccessNote]
+// CHECK:STDERR: fail_derived_to_base.carbon:[[@LINE+4]]:47: note: type `Incomplete*` does not implement interface `Core.ImplicitAs(A2*)` [MissingImplInMemberAccessNote]
 // CHECK:STDERR: fn ConvertIncomplete(p: Incomplete*) -> A2* { return p; }
 // CHECK:STDERR:                                               ^~~~~~~~~
+// CHECK:STDERR:
 fn ConvertIncomplete(p: Incomplete*) -> A2* { return p; }
 
 // CHECK:STDOUT: --- fail_derived_to_base.carbon
@@ -115,11 +116,11 @@ fn ConvertIncomplete(p: Incomplete*) -> A2* { return p; }
 // CHECK:STDOUT:     %return.param_patt: %ptr.590 = out_param_pattern %return.patt, runtime_param1
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %A2.ref: type = name_ref A2, file.%A2.decl [template = constants.%A2]
-// CHECK:STDOUT:     %ptr.loc41_43: type = ptr_type %A2 [template = constants.%ptr.590]
+// CHECK:STDOUT:     %ptr.loc42_43: type = ptr_type %A2 [template = constants.%ptr.590]
 // CHECK:STDOUT:     %p.param: %ptr.c62 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc41_35: type = splice_block %ptr.loc41_35 [template = constants.%ptr.c62] {
+// CHECK:STDOUT:     %.loc42_35: type = splice_block %ptr.loc42_35 [template = constants.%ptr.c62] {
 // CHECK:STDOUT:       %Incomplete.ref: type = name_ref Incomplete, file.%Incomplete.decl [template = constants.%Incomplete]
-// CHECK:STDOUT:       %ptr.loc41_35: type = ptr_type %Incomplete [template = constants.%ptr.c62]
+// CHECK:STDOUT:       %ptr.loc42_35: type = ptr_type %Incomplete [template = constants.%ptr.c62]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %p: %ptr.c62 = bind_name p, %p.param
 // CHECK:STDOUT:     %return.param: ref %ptr.590 = out_param runtime_param1
@@ -159,7 +160,7 @@ fn ConvertIncomplete(p: Incomplete*) -> A2* { return p; }
 // CHECK:STDOUT: fn @ConvertIncomplete(%p.param_patt: %ptr.c62) -> %ptr.590 {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %p.ref: %ptr.c62 = name_ref p, %p
-// CHECK:STDOUT:   %.loc41_55: %ptr.590 = converted %p.ref, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc42_55: %ptr.590 = converted %p.ref, <error> [template = <error>]
 // CHECK:STDOUT:   return <error>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/fail_extend_cycle.carbon b/toolchain/check/testdata/class/fail_extend_cycle.carbon
index 9d0db33004f6..1c2091fd97eb 100644
--- a/toolchain/check/testdata/class/fail_extend_cycle.carbon
+++ b/toolchain/check/testdata/class/fail_extend_cycle.carbon
@@ -25,9 +25,10 @@ base class B {
 // CHECK:STDERR:
 base class A {
   extend base: A;
-  // CHECK:STDERR: fail_extend_cycle.carbon:[[@LINE+3]]:10: error: name `C` not found [NameNotFound]
+  // CHECK:STDERR: fail_extend_cycle.carbon:[[@LINE+4]]:10: error: name `C` not found [NameNotFound]
   // CHECK:STDERR:   var c: C;
   // CHECK:STDERR:          ^
+  // CHECK:STDERR:
   var c: C;
 }
 
@@ -79,7 +80,7 @@ base class A {
 // CHECK:STDOUT: class @.1 {
 // CHECK:STDOUT:   %A.ref: type = name_ref A, file.%A.decl [template = constants.%A]
 // CHECK:STDOUT:   %.loc27: %.elem = base_decl %A.ref, element0 [template]
-// CHECK:STDOUT:   %.loc31: <error> = field_decl c, element1 [template]
+// CHECK:STDOUT:   %.loc32: <error> = field_decl c, element1 [template]
 // CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness <error> [template = <error>]
 // CHECK:STDOUT:   complete_type_witness = %complete_type
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/class/fail_field_modifiers.carbon b/toolchain/check/testdata/class/fail_field_modifiers.carbon
index 893883d3a0ac..fc174d10cfda 100644
--- a/toolchain/check/testdata/class/fail_field_modifiers.carbon
+++ b/toolchain/check/testdata/class/fail_field_modifiers.carbon
@@ -28,9 +28,10 @@ class Class {
   // CHECK:STDERR:
   default let l: i32 = 0;
 
-  // CHECK:STDERR: fail_field_modifiers.carbon:[[@LINE+3]]:3: error: `final` not allowed; requires interface scope [ModifierRequiresInterface]
+  // CHECK:STDERR: fail_field_modifiers.carbon:[[@LINE+4]]:3: error: `final` not allowed; requires interface scope [ModifierRequiresInterface]
   // CHECK:STDERR:   final let m: i32 = 1;
   // CHECK:STDERR:   ^~~~~
+  // CHECK:STDERR:
   final let m: i32 = 1;
 }
 
@@ -87,13 +88,13 @@ class Class {
 // CHECK:STDOUT:   %.loc29_25.2: %i32 = converted %int_0, %.loc29_25.1 [template = constants.%int_0.6a9]
 // CHECK:STDOUT:   %l: %i32 = bind_name l, %.loc29_25.2
 // CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [template = constants.%int_1.5b8]
-// CHECK:STDOUT:   %impl.elem0.loc34: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
-// CHECK:STDOUT:   %Convert.bound.loc34: <bound method> = bound_method %int_1, %impl.elem0.loc34 [template = constants.%Convert.bound.ab5]
-// CHECK:STDOUT:   %Convert.specific_fn.loc34: <specific function> = specific_function %Convert.bound.loc34, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.70c]
-// CHECK:STDOUT:   %int.convert_checked.loc34: init %i32 = call %Convert.specific_fn.loc34(%int_1) [template = constants.%int_1.5d2]
-// CHECK:STDOUT:   %.loc34_23.1: %i32 = value_of_initializer %int.convert_checked.loc34 [template = constants.%int_1.5d2]
-// CHECK:STDOUT:   %.loc34_23.2: %i32 = converted %int_1, %.loc34_23.1 [template = constants.%int_1.5d2]
-// CHECK:STDOUT:   %m: %i32 = bind_name m, %.loc34_23.2
+// CHECK:STDOUT:   %impl.elem0.loc35: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
+// CHECK:STDOUT:   %Convert.bound.loc35: <bound method> = bound_method %int_1, %impl.elem0.loc35 [template = constants.%Convert.bound.ab5]
+// CHECK:STDOUT:   %Convert.specific_fn.loc35: <specific function> = specific_function %Convert.bound.loc35, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.70c]
+// CHECK:STDOUT:   %int.convert_checked.loc35: init %i32 = call %Convert.specific_fn.loc35(%int_1) [template = constants.%int_1.5d2]
+// CHECK:STDOUT:   %.loc35_23.1: %i32 = value_of_initializer %int.convert_checked.loc35 [template = constants.%int_1.5d2]
+// CHECK:STDOUT:   %.loc35_23.2: %i32 = converted %int_1, %.loc35_23.1 [template = constants.%int_1.5d2]
+// CHECK:STDOUT:   %m: %i32 = bind_name m, %.loc35_23.2
 // CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %struct_type.j.k [template = constants.%complete_type.cf7]
 // CHECK:STDOUT:   complete_type_witness = %complete_type
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/class/fail_generic_method.carbon b/toolchain/check/testdata/class/fail_generic_method.carbon
index 56f0b659a5be..fcdfbe2f5404 100644
--- a/toolchain/check/testdata/class/fail_generic_method.carbon
+++ b/toolchain/check/testdata/class/fail_generic_method.carbon
@@ -15,20 +15,21 @@ class Class(T:! type) {
 
 // TODO: The follow-on errors here aren't great. Investigate whether we can
 // enter the scope anyway if the parameters don't match.
-// CHECK:STDERR: fail_generic_method.carbon:[[@LINE+14]]:10: error: type `i32` of parameter 1 in redeclaration differs from previous parameter type `type` [RedeclParamDiffersType]
+// CHECK:STDERR: fail_generic_method.carbon:[[@LINE+15]]:10: error: type `i32` of parameter 1 in redeclaration differs from previous parameter type `type` [RedeclParamDiffersType]
 // CHECK:STDERR: fn Class(N:! i32).F[self: Self](n: T) {}
 // CHECK:STDERR:          ^~~~~~~
 // CHECK:STDERR: fail_generic_method.carbon:[[@LINE-10]]:13: note: previous declaration's corresponding parameter here [RedeclParamPrevious]
 // CHECK:STDERR: class Class(T:! type) {
 // CHECK:STDERR:             ^~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_generic_method.carbon:[[@LINE+7]]:27: error: name `Self` not found [NameNotFound]
+// CHECK:STDERR: fail_generic_method.carbon:[[@LINE+8]]:27: error: name `Self` not found [NameNotFound]
 // CHECK:STDERR: fn Class(N:! i32).F[self: Self](n: T) {}
 // CHECK:STDERR:                           ^~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_generic_method.carbon:[[@LINE+3]]:36: error: name `T` not found [NameNotFound]
+// CHECK:STDERR: fail_generic_method.carbon:[[@LINE+4]]:36: error: name `T` not found [NameNotFound]
 // CHECK:STDERR: fn Class(N:! i32).F[self: Self](n: T) {}
 // CHECK:STDERR:                                    ^
+// CHECK:STDERR:
 fn Class(N:! i32).F[self: Self](n: T) {}
 
 // CHECK:STDOUT: --- fail_generic_method.carbon
@@ -81,11 +82,11 @@ fn Class(N:! i32).F[self: Self](n: T) {}
 // CHECK:STDOUT:     %n.param_patt: <error> = value_param_pattern %n.patt, runtime_param1
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %N.param: %i32 = value_param runtime_param<invalid>
-// CHECK:STDOUT:     %.loc32: type = splice_block %i32 [template = constants.%i32] {
+// CHECK:STDOUT:     %.loc33: type = splice_block %i32 [template = constants.%i32] {
 // CHECK:STDOUT:       %int_32: Core.IntLiteral = int_value 32 [template = constants.%int_32]
 // CHECK:STDOUT:       %i32: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
 // CHECK:STDOUT:     }
-// CHECK:STDOUT:     %N.loc32_10.1: %i32 = bind_symbolic_name N, 0, %N.param [symbolic = %N.loc32_10.2 (constants.%N.51e)]
+// CHECK:STDOUT:     %N.loc33_10.1: %i32 = bind_symbolic_name N, 0, %N.param [symbolic = %N.loc33_10.2 (constants.%N.51e)]
 // CHECK:STDOUT:     %self.param: <error> = value_param runtime_param0
 // CHECK:STDOUT:     %Self.ref: <error> = name_ref Self, <error> [template = <error>]
 // CHECK:STDOUT:     %self: <error> = bind_name self, %self.param
@@ -138,8 +139,8 @@ fn Class(N:! i32).F[self: Self](n: T) {}
 // CHECK:STDOUT:   fn[%self.param_patt: @F.%Class (%Class)](%n.param_patt: @F.%T (%T));
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: generic fn @.1(%N.loc32_10.1: %i32) {
-// CHECK:STDOUT:   %N.loc32_10.2: %i32 = bind_symbolic_name N, 0 [symbolic = %N.loc32_10.2 (constants.%N.51e)]
+// CHECK:STDOUT: generic fn @.1(%N.loc33_10.1: %i32) {
+// CHECK:STDOUT:   %N.loc33_10.2: %i32 = bind_symbolic_name N, 0 [symbolic = %N.loc33_10.2 (constants.%N.51e)]
 // CHECK:STDOUT:   %N.patt: %i32 = symbolic_binding_pattern N, 0 [symbolic = %N.patt (constants.%N.patt.8e2)]
 // CHECK:STDOUT:
 // CHECK:STDOUT: !definition:
@@ -165,7 +166,7 @@ fn Class(N:! i32).F[self: Self](n: T) {}
 // CHECK:STDOUT: specific @Class(%T.loc11_13.2) {}
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @.1(constants.%N.51e) {
-// CHECK:STDOUT:   %N.loc32_10.2 => constants.%N.51e
+// CHECK:STDOUT:   %N.loc33_10.2 => constants.%N.51e
 // CHECK:STDOUT:   %N.patt => constants.%N.51e
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/fail_import_misuses.carbon b/toolchain/check/testdata/class/fail_import_misuses.carbon
index 7f230b4e4236..5df8a33ad997 100644
--- a/toolchain/check/testdata/class/fail_import_misuses.carbon
+++ b/toolchain/check/testdata/class/fail_import_misuses.carbon
@@ -34,13 +34,14 @@ import library "a";
 class Empty {
 }
 
-// CHECK:STDERR: fail_b.carbon:[[@LINE+7]]:8: error: variable has incomplete type `Incomplete` [IncompleteTypeInVarDecl]
+// CHECK:STDERR: fail_b.carbon:[[@LINE+8]]:8: error: variable has incomplete type `Incomplete` [IncompleteTypeInVarDecl]
 // CHECK:STDERR: var a: Incomplete;
 // CHECK:STDERR:        ^~~~~~~~~~
 // CHECK:STDERR: fail_b.carbon:[[@LINE-16]]:1: in import [InImport]
 // CHECK:STDERR: a.carbon:7:1: note: class was forward declared here [ClassForwardDeclaredHere]
 // CHECK:STDERR: class Incomplete;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 var a: Incomplete;
 
 // CHECK:STDOUT: --- a.carbon
diff --git a/toolchain/check/testdata/class/fail_incomplete.carbon b/toolchain/check/testdata/class/fail_incomplete.carbon
index 746717d32eb1..7adfa1de309f 100644
--- a/toolchain/check/testdata/class/fail_incomplete.carbon
+++ b/toolchain/check/testdata/class/fail_incomplete.carbon
@@ -164,12 +164,13 @@ fn CallIncompleteAddrSelf(p: Class*) {
 library "[[@TEST_NAME]]";
 
 class C {
-  // CHECK:STDERR: fail_in_definition.carbon:[[@LINE+6]]:10: error: field has incomplete type `C` [IncompleteTypeInVarDecl]
+  // CHECK:STDERR: fail_in_definition.carbon:[[@LINE+7]]:10: error: field has incomplete type `C` [IncompleteTypeInVarDecl]
   // CHECK:STDERR:   var c: C;
   // CHECK:STDERR:          ^
   // CHECK:STDERR: fail_in_definition.carbon:[[@LINE-4]]:1: note: class is incomplete within its definition [ClassIncompleteWithinDefinition]
   // CHECK:STDERR: class C {
   // CHECK:STDERR: ^~~~~~~~~
+  // CHECK:STDERR:
   var c: C;
 }
 
@@ -481,7 +482,7 @@ class C {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: class @C {
-// CHECK:STDOUT:   %.loc11: <error> = field_decl c, element0 [template]
+// CHECK:STDOUT:   %.loc12: <error> = field_decl c, element0 [template]
 // CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness <error> [template = <error>]
 // CHECK:STDOUT:   complete_type_witness = %complete_type
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/class/fail_init.carbon b/toolchain/check/testdata/class/fail_init.carbon
index 7c30c7c8445b..41c788be0a3c 100644
--- a/toolchain/check/testdata/class/fail_init.carbon
+++ b/toolchain/check/testdata/class/fail_init.carbon
@@ -24,9 +24,10 @@ fn F() {
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~
   // CHECK:STDERR:
   {.a = 1, .c = 2} as Class;
-  // CHECK:STDERR: fail_init.carbon:[[@LINE+3]]:3: error: cannot initialize class with 2 fields from struct with 3 fields [StructInitElementCountMismatch]
+  // CHECK:STDERR: fail_init.carbon:[[@LINE+4]]:3: error: cannot initialize class with 2 fields from struct with 3 fields [StructInitElementCountMismatch]
   // CHECK:STDERR:   {.a = 1, .b = 2, .c = 3} as Class;
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   {.a = 1, .b = 2, .c = 3} as Class;
 }
 
@@ -105,14 +106,14 @@ fn F() {
 // CHECK:STDOUT:   %.loc26_18.5: init %i32 = initialize_from %.loc26_18.2 to %.loc26_18.4 [template = constants.%int_1.5d2]
 // CHECK:STDOUT:   %.loc26_18.6: ref %Class = temporary %.loc26_18.3, <error>
 // CHECK:STDOUT:   %.loc26_20: ref %Class = converted %.loc26_18.1, %.loc26_18.6
-// CHECK:STDOUT:   %int_1.loc30: Core.IntLiteral = int_value 1 [template = constants.%int_1.5b8]
-// CHECK:STDOUT:   %int_2.loc30: Core.IntLiteral = int_value 2 [template = constants.%int_2]
+// CHECK:STDOUT:   %int_1.loc31: Core.IntLiteral = int_value 1 [template = constants.%int_1.5b8]
+// CHECK:STDOUT:   %int_2.loc31: Core.IntLiteral = int_value 2 [template = constants.%int_2]
 // CHECK:STDOUT:   %int_3: Core.IntLiteral = int_value 3 [template = constants.%int_3]
-// CHECK:STDOUT:   %.loc30_26.1: %struct_type.a.b.c = struct_literal (%int_1.loc30, %int_2.loc30, %int_3)
-// CHECK:STDOUT:   %Class.ref.loc30: type = name_ref Class, file.%Class.decl [template = constants.%Class]
-// CHECK:STDOUT:   %.loc30_26.2: ref %Class = temporary_storage
-// CHECK:STDOUT:   %.loc30_26.3: ref %Class = temporary %.loc30_26.2, <error>
-// CHECK:STDOUT:   %.loc30_28: ref %Class = converted %.loc30_26.1, %.loc30_26.3
+// CHECK:STDOUT:   %.loc31_26.1: %struct_type.a.b.c = struct_literal (%int_1.loc31, %int_2.loc31, %int_3)
+// CHECK:STDOUT:   %Class.ref.loc31: type = name_ref Class, file.%Class.decl [template = constants.%Class]
+// CHECK:STDOUT:   %.loc31_26.2: ref %Class = temporary_storage
+// CHECK:STDOUT:   %.loc31_26.3: ref %Class = temporary %.loc31_26.2, <error>
+// CHECK:STDOUT:   %.loc31_28: ref %Class = converted %.loc31_26.1, %.loc31_26.3
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/fail_init_as_inplace.carbon b/toolchain/check/testdata/class/fail_init_as_inplace.carbon
index 2b85f2d18860..66adc4e9ee77 100644
--- a/toolchain/check/testdata/class/fail_init_as_inplace.carbon
+++ b/toolchain/check/testdata/class/fail_init_as_inplace.carbon
@@ -19,9 +19,10 @@ fn F() {
   // TODO: This case should presumably work: `{...} as Class` should be an
   // initializing expression, not a value expression.
   //
-  // CHECK:STDERR: fail_init_as_inplace.carbon:[[@LINE+3]]:18: error: cannot copy value of type `Class` [CopyOfUncopyableType]
+  // CHECK:STDERR: fail_init_as_inplace.carbon:[[@LINE+4]]:18: error: cannot copy value of type `Class` [CopyOfUncopyableType]
   // CHECK:STDERR:   var c: Class = {.a = 1, .b = 2} as Class;
   // CHECK:STDERR:                  ^~~~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   var c: Class = {.a = 1, .b = 2} as Class;
   G(&c);
 }
@@ -104,27 +105,27 @@ fn F() {
 // CHECK:STDOUT:   %c: ref %Class = bind_name c, %c.var
 // CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [template = constants.%int_1.5b8]
 // CHECK:STDOUT:   %int_2: Core.IntLiteral = int_value 2 [template = constants.%int_2.ecc]
-// CHECK:STDOUT:   %.loc25_33.1: %struct_type.a.b.cfd = struct_literal (%int_1, %int_2)
+// CHECK:STDOUT:   %.loc26_33.1: %struct_type.a.b.cfd = struct_literal (%int_1, %int_2)
 // CHECK:STDOUT:   %Class.ref: type = name_ref Class, file.%Class.decl [template = constants.%Class]
-// CHECK:STDOUT:   %impl.elem0.loc25_33.1: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
-// CHECK:STDOUT:   %Convert.bound.loc25_33.1: <bound method> = bound_method %int_1, %impl.elem0.loc25_33.1 [template = constants.%Convert.bound.ab5]
-// CHECK:STDOUT:   %Convert.specific_fn.loc25_33.1: <specific function> = specific_function %Convert.bound.loc25_33.1, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.70c]
-// CHECK:STDOUT:   %int.convert_checked.loc25_33.1: init %i32 = call %Convert.specific_fn.loc25_33.1(%int_1) [template = constants.%int_1.5d2]
-// CHECK:STDOUT:   %.loc25_33.2: init %i32 = converted %int_1, %int.convert_checked.loc25_33.1 [template = constants.%int_1.5d2]
-// CHECK:STDOUT:   %.loc25_33.3: ref %Class = temporary_storage
-// CHECK:STDOUT:   %.loc25_33.4: ref %i32 = class_element_access %.loc25_33.3, element0
-// CHECK:STDOUT:   %.loc25_33.5: init %i32 = initialize_from %.loc25_33.2 to %.loc25_33.4 [template = constants.%int_1.5d2]
-// CHECK:STDOUT:   %impl.elem0.loc25_33.2: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
-// CHECK:STDOUT:   %Convert.bound.loc25_33.2: <bound method> = bound_method %int_2, %impl.elem0.loc25_33.2 [template = constants.%Convert.bound.ef9]
-// CHECK:STDOUT:   %Convert.specific_fn.loc25_33.2: <specific function> = specific_function %Convert.bound.loc25_33.2, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.787]
-// CHECK:STDOUT:   %int.convert_checked.loc25_33.2: init %i32 = call %Convert.specific_fn.loc25_33.2(%int_2) [template = constants.%int_2.ef8]
-// CHECK:STDOUT:   %.loc25_33.6: init %i32 = converted %int_2, %int.convert_checked.loc25_33.2 [template = constants.%int_2.ef8]
-// CHECK:STDOUT:   %.loc25_33.7: ref %i32 = class_element_access %.loc25_33.3, element1
-// CHECK:STDOUT:   %.loc25_33.8: init %i32 = initialize_from %.loc25_33.6 to %.loc25_33.7 [template = constants.%int_2.ef8]
-// CHECK:STDOUT:   %.loc25_33.9: init %Class = class_init (%.loc25_33.5, %.loc25_33.8), %.loc25_33.3 [template = constants.%Class.val]
-// CHECK:STDOUT:   %.loc25_33.10: ref %Class = temporary %.loc25_33.3, %.loc25_33.9
-// CHECK:STDOUT:   %.loc25_35.1: ref %Class = converted %.loc25_33.1, %.loc25_33.10
-// CHECK:STDOUT:   %.loc25_35.2: %Class = bind_value %.loc25_35.1
+// CHECK:STDOUT:   %impl.elem0.loc26_33.1: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
+// CHECK:STDOUT:   %Convert.bound.loc26_33.1: <bound method> = bound_method %int_1, %impl.elem0.loc26_33.1 [template = constants.%Convert.bound.ab5]
+// CHECK:STDOUT:   %Convert.specific_fn.loc26_33.1: <specific function> = specific_function %Convert.bound.loc26_33.1, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.70c]
+// CHECK:STDOUT:   %int.convert_checked.loc26_33.1: init %i32 = call %Convert.specific_fn.loc26_33.1(%int_1) [template = constants.%int_1.5d2]
+// CHECK:STDOUT:   %.loc26_33.2: init %i32 = converted %int_1, %int.convert_checked.loc26_33.1 [template = constants.%int_1.5d2]
+// CHECK:STDOUT:   %.loc26_33.3: ref %Class = temporary_storage
+// CHECK:STDOUT:   %.loc26_33.4: ref %i32 = class_element_access %.loc26_33.3, element0
+// CHECK:STDOUT:   %.loc26_33.5: init %i32 = initialize_from %.loc26_33.2 to %.loc26_33.4 [template = constants.%int_1.5d2]
+// CHECK:STDOUT:   %impl.elem0.loc26_33.2: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
+// CHECK:STDOUT:   %Convert.bound.loc26_33.2: <bound method> = bound_method %int_2, %impl.elem0.loc26_33.2 [template = constants.%Convert.bound.ef9]
+// CHECK:STDOUT:   %Convert.specific_fn.loc26_33.2: <specific function> = specific_function %Convert.bound.loc26_33.2, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.787]
+// CHECK:STDOUT:   %int.convert_checked.loc26_33.2: init %i32 = call %Convert.specific_fn.loc26_33.2(%int_2) [template = constants.%int_2.ef8]
+// CHECK:STDOUT:   %.loc26_33.6: init %i32 = converted %int_2, %int.convert_checked.loc26_33.2 [template = constants.%int_2.ef8]
+// CHECK:STDOUT:   %.loc26_33.7: ref %i32 = class_element_access %.loc26_33.3, element1
+// CHECK:STDOUT:   %.loc26_33.8: init %i32 = initialize_from %.loc26_33.6 to %.loc26_33.7 [template = constants.%int_2.ef8]
+// CHECK:STDOUT:   %.loc26_33.9: init %Class = class_init (%.loc26_33.5, %.loc26_33.8), %.loc26_33.3 [template = constants.%Class.val]
+// CHECK:STDOUT:   %.loc26_33.10: ref %Class = temporary %.loc26_33.3, %.loc26_33.9
+// CHECK:STDOUT:   %.loc26_35.1: ref %Class = converted %.loc26_33.1, %.loc26_33.10
+// CHECK:STDOUT:   %.loc26_35.2: %Class = bind_value %.loc26_35.1
 // CHECK:STDOUT:   assign %c.var, <error>
 // CHECK:STDOUT:   %G.ref: %G.type = name_ref G, file.%G.decl [template = constants.%G]
 // CHECK:STDOUT:   %c.ref: ref %Class = name_ref c, %c
diff --git a/toolchain/check/testdata/class/fail_memaccess_category.carbon b/toolchain/check/testdata/class/fail_memaccess_category.carbon
index 712305b22cfe..b0d206d007b4 100644
--- a/toolchain/check/testdata/class/fail_memaccess_category.carbon
+++ b/toolchain/check/testdata/class/fail_memaccess_category.carbon
@@ -29,12 +29,13 @@ fn F(s: {.a: A}, b: B) {
 
   // `b` has an object representation for `A`, but this is still invalid for
   // consistency.
-  // CHECK:STDERR: fail_memaccess_category.carbon:[[@LINE+6]]:4: error: `addr self` method cannot be invoked on a value [AddrSelfIsNonRef]
+  // CHECK:STDERR: fail_memaccess_category.carbon:[[@LINE+7]]:4: error: `addr self` method cannot be invoked on a value [AddrSelfIsNonRef]
   // CHECK:STDERR:   b.a.F();
   // CHECK:STDERR:    ^
   // CHECK:STDERR: fail_memaccess_category.carbon:[[@LINE-23]]:8: note: initializing function parameter [InCallToFunctionParam]
   // CHECK:STDERR:   fn F[addr self: A*]();
   // CHECK:STDERR:        ^~~~~~~~~~~~~
+  // CHECK:STDERR:
   b.a.F();
 }
 
@@ -125,11 +126,11 @@ fn F(s: {.a: A}, b: B) {
 // CHECK:STDOUT:   %F.call.loc28: init %empty_tuple.type = call %F.bound.loc28(<error>)
 // CHECK:STDOUT:   %b.ref: %B = name_ref b, %b
 // CHECK:STDOUT:   %a.ref: %B.elem = name_ref a, @B.%.loc16 [template = @B.%.loc16]
-// CHECK:STDOUT:   %.loc38_4.1: ref %A = class_element_access %b.ref, element0
-// CHECK:STDOUT:   %.loc38_4.2: %A = bind_value %.loc38_4.1
-// CHECK:STDOUT:   %F.ref.loc38: %F.type.649 = name_ref F, @A.%F.decl [template = constants.%F.485]
-// CHECK:STDOUT:   %F.bound.loc38: <bound method> = bound_method %.loc38_4.2, %F.ref.loc38
-// CHECK:STDOUT:   %F.call.loc38: init %empty_tuple.type = call %F.bound.loc38(<error>)
+// CHECK:STDOUT:   %.loc39_4.1: ref %A = class_element_access %b.ref, element0
+// CHECK:STDOUT:   %.loc39_4.2: %A = bind_value %.loc39_4.1
+// CHECK:STDOUT:   %F.ref.loc39: %F.type.649 = name_ref F, @A.%F.decl [template = constants.%F.485]
+// CHECK:STDOUT:   %F.bound.loc39: <bound method> = bound_method %.loc39_4.2, %F.ref.loc39
+// CHECK:STDOUT:   %F.call.loc39: init %empty_tuple.type = call %F.bound.loc39(<error>)
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/fail_member_of_let.carbon b/toolchain/check/testdata/class/fail_member_of_let.carbon
index ac1fbaf9c764..f227873961e7 100644
--- a/toolchain/check/testdata/class/fail_member_of_let.carbon
+++ b/toolchain/check/testdata/class/fail_member_of_let.carbon
@@ -17,12 +17,13 @@ let T: type = Class;
 
 // The class name is required to be written in the same way as in the class
 // declaration. An expression that evaluates to the class name is not accepted.
-// CHECK:STDERR: fail_member_of_let.carbon:[[@LINE+6]]:4: error: name qualifiers are only allowed for entities that provide a scope [QualifiedNameInNonScope]
+// CHECK:STDERR: fail_member_of_let.carbon:[[@LINE+7]]:4: error: name qualifiers are only allowed for entities that provide a scope [QualifiedNameInNonScope]
 // CHECK:STDERR: fn T.F() {}
 // CHECK:STDERR:    ^
 // CHECK:STDERR: fail_member_of_let.carbon:[[@LINE-7]]:5: note: referenced non-scope entity declared here [QualifiedNameNonScopeEntity]
 // CHECK:STDERR: let T: type = Class;
 // CHECK:STDERR:     ^
+// CHECK:STDERR:
 fn T.F() {}
 
 // CHECK:STDOUT: --- fail_member_of_let.carbon
diff --git a/toolchain/check/testdata/class/fail_method.carbon b/toolchain/check/testdata/class/fail_method.carbon
index f10840fcf7bb..3a0d08b05808 100644
--- a/toolchain/check/testdata/class/fail_method.carbon
+++ b/toolchain/check/testdata/class/fail_method.carbon
@@ -37,12 +37,13 @@ fn F(c: Class) {
   // CHECK:STDERR:
   Class.WithSelf(c);
 
-  // CHECK:STDERR: fail_method.carbon:[[@LINE+6]]:3: error: missing object argument in method call [MissingObjectInMethodCall]
+  // CHECK:STDERR: fail_method.carbon:[[@LINE+7]]:3: error: missing object argument in method call [MissingObjectInMethodCall]
   // CHECK:STDERR:   A();
   // CHECK:STDERR:   ^~~
   // CHECK:STDERR: fail_method.carbon:[[@LINE-30]]:3: note: calling function declared here [InCallToFunction]
   // CHECK:STDERR:   fn WithSelf[self: Class]();
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   A();
 }
 
@@ -127,7 +128,7 @@ fn F(c: Class) {
 // CHECK:STDOUT:   %WithSelf.ref.loc38: %WithSelf.type = name_ref WithSelf, @Class.%WithSelf.decl [template = constants.%WithSelf]
 // CHECK:STDOUT:   %c.ref.loc38: %Class = name_ref c, %c
 // CHECK:STDOUT:   %A.ref: %WithSelf.type = name_ref A, file.%A [template = constants.%WithSelf]
-// CHECK:STDOUT:   %WithSelf.call.loc46: init %empty_tuple.type = call %A.ref(<error>)
+// CHECK:STDOUT:   %WithSelf.call.loc47: init %empty_tuple.type = call %A.ref(<error>)
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/fail_method_modifiers.carbon b/toolchain/check/testdata/class/fail_method_modifiers.carbon
index 3e6ae7d08d77..cfb972856cf4 100644
--- a/toolchain/check/testdata/class/fail_method_modifiers.carbon
+++ b/toolchain/check/testdata/class/fail_method_modifiers.carbon
@@ -46,12 +46,13 @@ abstract class AbstractClass {
 
 base class BaseClass {
 
-  // CHECK:STDERR: fail_method_modifiers.carbon:[[@LINE+6]]:3: error: `abstract` not allowed; requires `abstract` class scope [ModifierAbstractNotAllowed]
+  // CHECK:STDERR: fail_method_modifiers.carbon:[[@LINE+7]]:3: error: `abstract` not allowed; requires `abstract` class scope [ModifierAbstractNotAllowed]
   // CHECK:STDERR:   abstract fn Abstract[self: Self]();
   // CHECK:STDERR:   ^~~~~~~~
   // CHECK:STDERR: fail_method_modifiers.carbon:[[@LINE-5]]:1: note: containing definition here [ModifierNotInContext]
   // CHECK:STDERR: base class BaseClass {
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   abstract fn Abstract[self: Self]();
 }
 
diff --git a/toolchain/check/testdata/class/fail_method_redefinition.carbon b/toolchain/check/testdata/class/fail_method_redefinition.carbon
index 13cde1911788..fe67182ef340 100644
--- a/toolchain/check/testdata/class/fail_method_redefinition.carbon
+++ b/toolchain/check/testdata/class/fail_method_redefinition.carbon
@@ -10,12 +10,13 @@
 
 class Class {
   fn F() {}
-  // CHECK:STDERR: fail_method_redefinition.carbon:[[@LINE+6]]:3: error: redefinition of `fn F` [RedeclRedef]
+  // CHECK:STDERR: fail_method_redefinition.carbon:[[@LINE+7]]:3: error: redefinition of `fn F` [RedeclRedef]
   // CHECK:STDERR:   fn F() {}
   // CHECK:STDERR:   ^~~~~~~~
   // CHECK:STDERR: fail_method_redefinition.carbon:[[@LINE-4]]:3: note: previously defined here [RedeclPrevDef]
   // CHECK:STDERR:   fn F() {}
   // CHECK:STDERR:   ^~~~~~~~
+  // CHECK:STDERR:
   fn F() {}
 }
 
diff --git a/toolchain/check/testdata/class/fail_modifiers.carbon b/toolchain/check/testdata/class/fail_modifiers.carbon
index c52e72c01fcf..2df159ace7bf 100644
--- a/toolchain/check/testdata/class/fail_modifiers.carbon
+++ b/toolchain/check/testdata/class/fail_modifiers.carbon
@@ -90,9 +90,10 @@ abstract class AbstractWithDefinition {
   abstract fn F() {}
   abstract fn G();
 }
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+3]]:31: error: definition of `abstract` function [DefinedAbstractFunction]
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+4]]:31: error: definition of `abstract` function [DefinedAbstractFunction]
 // CHECK:STDERR: fn AbstractWithDefinition.G() {
 // CHECK:STDERR:                               ^
+// CHECK:STDERR:
 fn AbstractWithDefinition.G() {
 }
 
diff --git a/toolchain/check/testdata/class/fail_out_of_line_decl.carbon b/toolchain/check/testdata/class/fail_out_of_line_decl.carbon
index 98717eefe8f2..83a60d3e2cfd 100644
--- a/toolchain/check/testdata/class/fail_out_of_line_decl.carbon
+++ b/toolchain/check/testdata/class/fail_out_of_line_decl.carbon
@@ -10,9 +10,10 @@
 
 class C {}
 
-// CHECK:STDERR: fail_out_of_line_decl.carbon:[[@LINE+3]]:6: error: out-of-line declaration requires a declaration in scoped entity [QualifiedDeclOutsideScopeEntity]
+// CHECK:STDERR: fail_out_of_line_decl.carbon:[[@LINE+4]]:6: error: out-of-line declaration requires a declaration in scoped entity [QualifiedDeclOutsideScopeEntity]
 // CHECK:STDERR: fn C.F() {}
 // CHECK:STDERR:      ^
+// CHECK:STDERR:
 fn C.F() {}
 
 // CHECK:STDOUT: --- fail_out_of_line_decl.carbon
diff --git a/toolchain/check/testdata/class/fail_redeclaration_scope.carbon b/toolchain/check/testdata/class/fail_redeclaration_scope.carbon
index 43fd9e7b24a7..16d448522b2b 100644
--- a/toolchain/check/testdata/class/fail_redeclaration_scope.carbon
+++ b/toolchain/check/testdata/class/fail_redeclaration_scope.carbon
@@ -19,9 +19,10 @@ class X {
 class A { class B; }
 
 class Y {
-  // CHECK:STDERR: fail_redeclaration_scope.carbon:[[@LINE+3]]:9: error: name `A` not found [NameNotFound]
+  // CHECK:STDERR: fail_redeclaration_scope.carbon:[[@LINE+4]]:9: error: name `A` not found [NameNotFound]
   // CHECK:STDERR:   class A.B {}
   // CHECK:STDERR:         ^
+  // CHECK:STDERR:
   class A.B {}
 }
 
diff --git a/toolchain/check/testdata/class/fail_redefinition.carbon b/toolchain/check/testdata/class/fail_redefinition.carbon
index 2ef4eda412b8..e53962ab90de 100644
--- a/toolchain/check/testdata/class/fail_redefinition.carbon
+++ b/toolchain/check/testdata/class/fail_redefinition.carbon
@@ -34,12 +34,13 @@ fn Class.F() {}
 // CHECK:STDERR:
 fn Class.G() {}
 fn Class.H() {}
-// CHECK:STDERR: fail_redefinition.carbon:[[@LINE+6]]:1: error: redefinition of `fn I` [RedeclRedef]
+// CHECK:STDERR: fail_redefinition.carbon:[[@LINE+7]]:1: error: redefinition of `fn I` [RedeclRedef]
 // CHECK:STDERR: fn Class.I() {}
 // CHECK:STDERR: ^~~~~~~~~~~~~~
 // CHECK:STDERR: fail_redefinition.carbon:[[@LINE-26]]:3: note: previously defined here [RedeclPrevDef]
 // CHECK:STDERR:   fn I() {}
 // CHECK:STDERR:   ^~~~~~~~
+// CHECK:STDERR:
 fn Class.I() {}
 
 // CHECK:STDOUT: --- fail_redefinition.carbon
@@ -85,7 +86,7 @@ fn Class.I() {}
 // CHECK:STDOUT:   %F.decl: %F.type = fn_decl @F [template = constants.%F] {} {}
 // CHECK:STDOUT:   %G.decl: %G.type.621 = fn_decl @G.2 [template = constants.%G.f0c] {} {}
 // CHECK:STDOUT:   %H.decl: %H.type.91d = fn_decl @H.1 [template = constants.%H.d38] {} {}
-// CHECK:STDOUT:   %.decl.loc43: %.type = fn_decl @.1 [template = constants.%.d22] {} {}
+// CHECK:STDOUT:   %.decl.loc44: %.type = fn_decl @.1 [template = constants.%.d22] {} {}
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: class @Class {
diff --git a/toolchain/check/testdata/class/fail_scope.carbon b/toolchain/check/testdata/class/fail_scope.carbon
index 88b10ca2b895..47d9fcf295a0 100644
--- a/toolchain/check/testdata/class/fail_scope.carbon
+++ b/toolchain/check/testdata/class/fail_scope.carbon
@@ -15,9 +15,10 @@ class Class {
 }
 
 fn G() -> i32 {
-  // CHECK:STDERR: fail_scope.carbon:[[@LINE+3]]:10: error: name `F` not found [NameNotFound]
+  // CHECK:STDERR: fail_scope.carbon:[[@LINE+4]]:10: error: name `F` not found [NameNotFound]
   // CHECK:STDERR:   return F();
   // CHECK:STDERR:          ^
+  // CHECK:STDERR:
   return F();
 }
 
diff --git a/toolchain/check/testdata/class/fail_self.carbon b/toolchain/check/testdata/class/fail_self.carbon
index 3bcc7033613d..656a178316e7 100644
--- a/toolchain/check/testdata/class/fail_self.carbon
+++ b/toolchain/check/testdata/class/fail_self.carbon
@@ -43,15 +43,16 @@ class WrongSelf {
 }
 
 fn CallWrongSelf(ws: WrongSelf) {
-  // CHECK:STDERR: fail_self.carbon:[[@LINE+9]]:3: error: cannot implicitly convert from `WrongSelf` to `Class` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_self.carbon:[[@LINE+10]]:3: error: cannot implicitly convert from `WrongSelf` to `Class` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   ws.F();
   // CHECK:STDERR:   ^~
-  // CHECK:STDERR: fail_self.carbon:[[@LINE+6]]:3: note: type `WrongSelf` does not implement interface `Core.ImplicitAs(Class)` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR: fail_self.carbon:[[@LINE+7]]:3: note: type `WrongSelf` does not implement interface `Core.ImplicitAs(Class)` [MissingImplInMemberAccessNote]
   // CHECK:STDERR:   ws.F();
   // CHECK:STDERR:   ^~
   // CHECK:STDERR: fail_self.carbon:[[@LINE-10]]:8: note: initializing function parameter [InCallToFunctionParam]
   // CHECK:STDERR:   fn F[self: Class]();
   // CHECK:STDERR:        ^~~~~~~~~~~
+  // CHECK:STDERR:
   ws.F();
 }
 
@@ -172,7 +173,7 @@ fn CallWrongSelf(ws: WrongSelf) {
 // CHECK:STDOUT:   %ws.ref: %WrongSelf = name_ref ws, %ws
 // CHECK:STDOUT:   %F.ref: %F.type.25f = name_ref F, @WrongSelf.%F.decl [template = constants.%F.3a3]
 // CHECK:STDOUT:   %F.bound: <bound method> = bound_method %ws.ref, %F.ref
-// CHECK:STDOUT:   %.loc55: %Class = converted %ws.ref, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc56: %Class = converted %ws.ref, <error> [template = <error>]
 // CHECK:STDOUT:   %F.call: init %empty_tuple.type = call %F.bound(<error>)
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/class/fail_self_param.carbon b/toolchain/check/testdata/class/fail_self_param.carbon
index 8abd9dab734c..8a73a5ac3f2d 100644
--- a/toolchain/check/testdata/class/fail_self_param.carbon
+++ b/toolchain/check/testdata/class/fail_self_param.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/fail_self_param.carbon
 
-// CHECK:STDERR: fail_self_param.carbon:[[@LINE+3]]:9: error: `self` parameter only allowed on functions [SelfParameterNotAllowed]
+// CHECK:STDERR: fail_self_param.carbon:[[@LINE+4]]:9: error: `self` parameter only allowed on functions [SelfParameterNotAllowed]
 // CHECK:STDERR: class C[self:! type](x:! self) {}
 // CHECK:STDERR:         ^~~~~~~~~~~
+// CHECK:STDERR:
 class C[self:! type](x:! self) {}
 var v: C(0);
 
@@ -39,8 +40,8 @@ var v: C(0);
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %Core.import = import Core
 // CHECK:STDOUT:   %C.decl: %C.type = class_decl @C [template = constants.%C.generic] {
-// CHECK:STDOUT:     %x.patt.loc14_22.1: <error> = symbolic_binding_pattern x, 0 [symbolic = %x.patt.loc14_22.2 (constants.%x.patt)]
-// CHECK:STDOUT:     %x.param_patt: <error> = value_param_pattern %x.patt.loc14_22.1, runtime_param<invalid> [symbolic = %x.patt.loc14_22.2 (constants.%x.patt)]
+// CHECK:STDOUT:     %x.patt.loc15_22.1: <error> = symbolic_binding_pattern x, 0 [symbolic = %x.patt.loc15_22.2 (constants.%x.patt)]
+// CHECK:STDOUT:     %x.param_patt: <error> = value_param_pattern %x.patt.loc15_22.1, runtime_param<invalid> [symbolic = %x.patt.loc15_22.2 (constants.%x.patt)]
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %x.param: <error> = value_param runtime_param<invalid>
 // CHECK:STDOUT:     %self.ref: <error> = name_ref self, <error> [template = <error>]
@@ -51,7 +52,7 @@ var v: C(0);
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: generic class @C(%x: <error>) {
-// CHECK:STDOUT:   %x.patt.loc14_22.2: <error> = symbolic_binding_pattern x, 0 [symbolic = %x.patt.loc14_22.2 (constants.%x.patt)]
+// CHECK:STDOUT:   %x.patt.loc15_22.2: <error> = symbolic_binding_pattern x, 0 [symbolic = %x.patt.loc15_22.2 (constants.%x.patt)]
 // CHECK:STDOUT:
 // CHECK:STDOUT: !definition:
 // CHECK:STDOUT:
@@ -62,6 +63,6 @@ var v: C(0);
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @C(<error>) {
-// CHECK:STDOUT:   %x.patt.loc14_22.2 => <error>
+// CHECK:STDOUT:   %x.patt.loc15_22.2 => <error>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/fail_self_type_member.carbon b/toolchain/check/testdata/class/fail_self_type_member.carbon
index 35cc0774eff0..a22737d3eb16 100644
--- a/toolchain/check/testdata/class/fail_self_type_member.carbon
+++ b/toolchain/check/testdata/class/fail_self_type_member.carbon
@@ -14,13 +14,14 @@ class Class {
 
 fn F() -> bool {
   var c1: Class = {.b = true};
-  // CHECK:STDERR: fail_self_type_member.carbon:[[@LINE+7]]:17: error: expected identifier after `.` [ExpectedIdentifierAfterPeriodOrArrow]
+  // CHECK:STDERR: fail_self_type_member.carbon:[[@LINE+8]]:17: error: expected identifier after `.` [ExpectedIdentifierAfterPeriodOrArrow]
   // CHECK:STDERR:   var c2: Class.Self = c1;
   // CHECK:STDERR:                 ^~~~
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_self_type_member.carbon:[[@LINE+3]]:17: error: semantics TODO: `handle invalid parse trees in `check`` [SemanticsTodo]
+  // CHECK:STDERR: fail_self_type_member.carbon:[[@LINE+4]]:17: error: semantics TODO: `handle invalid parse trees in `check`` [SemanticsTodo]
   // CHECK:STDERR:   var c2: Class.Self = c1;
   // CHECK:STDERR:                 ^~~~
+  // CHECK:STDERR:
   var c2: Class.Self = c1;
   return c2.b;
 }
diff --git a/toolchain/check/testdata/class/fail_unbound_field.carbon b/toolchain/check/testdata/class/fail_unbound_field.carbon
index 6ed67eeb3a52..bf0d1be4d999 100644
--- a/toolchain/check/testdata/class/fail_unbound_field.carbon
+++ b/toolchain/check/testdata/class/fail_unbound_field.carbon
@@ -20,9 +20,10 @@ class Class {
 }
 
 fn G() -> i32 {
-  // CHECK:STDERR: fail_unbound_field.carbon:[[@LINE+3]]:10: error: expression cannot be used as a value [UseOfNonExprAsValue]
+  // CHECK:STDERR: fail_unbound_field.carbon:[[@LINE+4]]:10: error: expression cannot be used as a value [UseOfNonExprAsValue]
   // CHECK:STDERR:   return Class.field;
   // CHECK:STDERR:          ^~~~~~~~~~~
+  // CHECK:STDERR:
   return Class.field;
 }
 
diff --git a/toolchain/check/testdata/class/fail_unknown_member.carbon b/toolchain/check/testdata/class/fail_unknown_member.carbon
index 1324ea11f631..42dfc06697cf 100644
--- a/toolchain/check/testdata/class/fail_unknown_member.carbon
+++ b/toolchain/check/testdata/class/fail_unknown_member.carbon
@@ -14,9 +14,10 @@ class Class {
 
 fn G(c: Class) -> i32 {
   // TODO: Mention the scope in which we looked for the name.
-  // CHECK:STDERR: fail_unknown_member.carbon:[[@LINE+3]]:10: error: member name `something` not found in `Class` [MemberNameNotFoundInScope]
+  // CHECK:STDERR: fail_unknown_member.carbon:[[@LINE+4]]:10: error: member name `something` not found in `Class` [MemberNameNotFoundInScope]
   // CHECK:STDERR:   return c.something;
   // CHECK:STDERR:          ^~~~~~~~~~~
+  // CHECK:STDERR:
   return c.something;
 }
 
diff --git a/toolchain/check/testdata/class/generic/adapt.carbon b/toolchain/check/testdata/class/generic/adapt.carbon
index 2e885f1de42f..7fdb5bf91bb2 100644
--- a/toolchain/check/testdata/class/generic/adapt.carbon
+++ b/toolchain/check/testdata/class/generic/adapt.carbon
@@ -81,12 +81,13 @@ import library "extend_adapt_specific_type_library";
 
 fn ImportedAccess(a: Adapter) -> i32 {
   // TODO: This should presumably work, but the design doesn't say how yet.
-  // CHECK:STDERR: fail_todo_import_extend_adapt_specific_type.carbon:[[@LINE+6]]:10: error: cannot implicitly convert from `Adapter` to `C(i32)` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_todo_import_extend_adapt_specific_type.carbon:[[@LINE+7]]:10: error: cannot implicitly convert from `Adapter` to `C(i32)` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   return a.x;
   // CHECK:STDERR:          ^~~
-  // CHECK:STDERR: fail_todo_import_extend_adapt_specific_type.carbon:[[@LINE+3]]:10: note: type `Adapter` does not implement interface `Core.ImplicitAs(C(i32))` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR: fail_todo_import_extend_adapt_specific_type.carbon:[[@LINE+4]]:10: note: type `Adapter` does not implement interface `Core.ImplicitAs(C(i32))` [MissingImplInMemberAccessNote]
   // CHECK:STDERR:   return a.x;
   // CHECK:STDERR:          ^~~
+  // CHECK:STDERR:
   return a.x;
 }
 
@@ -669,8 +670,8 @@ fn ImportedConvertLocal(a: Adapter(C)) -> i32 {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %a.ref: %Adapter = name_ref a, %a
 // CHECK:STDOUT:   %x.ref: %C.elem.ed6 = name_ref x, imports.%import_ref.262 [template = imports.%.22b]
-// CHECK:STDOUT:   %.loc14_11.1: %C.239 = converted %a.ref, <error> [template = <error>]
-// CHECK:STDOUT:   %.loc14_11.2: %i32 = class_element_access <error>, element0 [template = <error>]
+// CHECK:STDOUT:   %.loc15_11.1: %C.239 = converted %a.ref, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc15_11.2: %i32 = class_element_access <error>, element0 [template = <error>]
 // CHECK:STDOUT:   return <error>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/generic/base_is_generic.carbon b/toolchain/check/testdata/class/generic/base_is_generic.carbon
index 9ffe2b222674..81522f720c2d 100644
--- a/toolchain/check/testdata/class/generic/base_is_generic.carbon
+++ b/toolchain/check/testdata/class/generic/base_is_generic.carbon
@@ -43,9 +43,10 @@ fn ImportedDoubleFieldAccess(d: Derived) -> i32 {
 library "[[@TEST_NAME]]";
 
 class C(T:! type) {
-  // CHECK:STDERR: fail_todo_extend_symbolic_base.carbon:[[@LINE+3]]:16: error: deriving from final type `T`; base type must be an `abstract` or `base` class [BaseIsFinal]
+  // CHECK:STDERR: fail_todo_extend_symbolic_base.carbon:[[@LINE+4]]:16: error: deriving from final type `T`; base type must be an `abstract` or `base` class [BaseIsFinal]
   // CHECK:STDERR:   extend base: T;
   // CHECK:STDERR:                ^
+  // CHECK:STDERR:
   extend base: T;
 }
 
@@ -401,7 +402,7 @@ fn H() {
 // CHECK:STDOUT:
 // CHECK:STDOUT:   class {
 // CHECK:STDOUT:     %T.ref: type = name_ref T, %T.loc4_9.1 [symbolic = %T.loc4_9.2 (constants.%T)]
-// CHECK:STDOUT:     %.loc8: <error> = base_decl <error>, element0 [template]
+// CHECK:STDOUT:     %.loc9: <error> = base_decl <error>, element0 [template]
 // CHECK:STDOUT:     %complete_type: <witness> = complete_type_witness <error> [template = <error>]
 // CHECK:STDOUT:     complete_type_witness = %complete_type
 // CHECK:STDOUT:   }
diff --git a/toolchain/check/testdata/class/generic/call.carbon b/toolchain/check/testdata/class/generic/call.carbon
index aaa7591f81a5..eb70faa00951 100644
--- a/toolchain/check/testdata/class/generic/call.carbon
+++ b/toolchain/check/testdata/class/generic/call.carbon
@@ -55,15 +55,16 @@ library "[[@TEST_NAME]]";
 
 class Class(T:! type, N:! i32) {}
 
-// CHECK:STDERR: fail_no_conversion.carbon:[[@LINE+9]]:8: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_no_conversion.carbon:[[@LINE+10]]:8: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var a: Class(5, i32*);
 // CHECK:STDERR:        ^~~~~~~~~~~~~~
-// CHECK:STDERR: fail_no_conversion.carbon:[[@LINE+6]]:8: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
+// CHECK:STDERR: fail_no_conversion.carbon:[[@LINE+7]]:8: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
 // CHECK:STDERR: var a: Class(5, i32*);
 // CHECK:STDERR:        ^~~~~~~~~~~~~~
 // CHECK:STDERR: fail_no_conversion.carbon:[[@LINE-8]]:1: note: while deducing parameters of generic declared here [DeductionGenericHere]
 // CHECK:STDERR: class Class(T:! type, N:! i32) {}
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 var a: Class(5, i32*);
 
 // --- call_in_nested_return_type.carbon
diff --git a/toolchain/check/testdata/class/generic/complete_in_conversion.carbon b/toolchain/check/testdata/class/generic/complete_in_conversion.carbon
index 32a3e14f3432..38b53e508424 100644
--- a/toolchain/check/testdata/class/generic/complete_in_conversion.carbon
+++ b/toolchain/check/testdata/class/generic/complete_in_conversion.carbon
@@ -24,9 +24,10 @@ class A(N:! i32) {
 }
 
 fn F(a: A(0)*) {
-  // CHECK:STDERR: fail_derived_to_base.carbon:[[@LINE+3]]:3: note: in `A(0)` used here [ResolvingSpecificHere]
+  // CHECK:STDERR: fail_derived_to_base.carbon:[[@LINE+4]]:3: note: in `A(0)` used here [ResolvingSpecificHere]
   // CHECK:STDERR:   let b: B* = a;
   // CHECK:STDERR:   ^~~~~~~~~~~~~~
+  // CHECK:STDERR:
   let b: B* = a;
 }
 
@@ -182,11 +183,11 @@ fn F(a: A(0)*) {
 // CHECK:STDOUT: fn @F(%a.param_patt: %ptr.b65) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %a.ref: %ptr.b65 = name_ref a, %a
-// CHECK:STDOUT:   %.loc19_16.1: ref %A.6fc = deref %a.ref
-// CHECK:STDOUT:   %.loc19_16.2: ref %B = class_element_access %.loc19_16.1, element0
-// CHECK:STDOUT:   %addr: %ptr.e79 = addr_of %.loc19_16.2
-// CHECK:STDOUT:   %.loc19_16.3: %ptr.e79 = converted %a.ref, %addr
-// CHECK:STDOUT:   %b: %ptr.e79 = bind_name b, %.loc19_16.3
+// CHECK:STDOUT:   %.loc20_16.1: ref %A.6fc = deref %a.ref
+// CHECK:STDOUT:   %.loc20_16.2: ref %B = class_element_access %.loc20_16.1, element0
+// CHECK:STDOUT:   %addr: %ptr.e79 = addr_of %.loc20_16.2
+// CHECK:STDOUT:   %.loc20_16.3: %ptr.e79 = converted %a.ref, %addr
+// CHECK:STDOUT:   %b: %ptr.e79 = bind_name b, %.loc20_16.3
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/generic/import.carbon b/toolchain/check/testdata/class/generic/import.carbon
index 95f1a2c824b9..ce7df86ab5f3 100644
--- a/toolchain/check/testdata/class/generic/import.carbon
+++ b/toolchain/check/testdata/class/generic/import.carbon
@@ -78,9 +78,10 @@ impl library "[[@TEST_NAME]]";
 // CHECK:STDERR:             ^~~~~~~~
 // CHECK:STDERR:
 class Class(U:! type) {
-  // CHECK:STDERR: fail_foo.impl.carbon:[[@LINE+3]]:10: error: name `T` not found [NameNotFound]
+  // CHECK:STDERR: fail_foo.impl.carbon:[[@LINE+4]]:10: error: name `T` not found [NameNotFound]
   // CHECK:STDERR:   var x: T;
   // CHECK:STDERR:          ^
+  // CHECK:STDERR:
   var x: T;
 }
 
@@ -746,7 +747,7 @@ class Class(U:! type) {
 // CHECK:STDOUT: !definition:
 // CHECK:STDOUT:
 // CHECK:STDOUT:   class {
-// CHECK:STDOUT:     %.loc16: <error> = field_decl x, element0 [template]
+// CHECK:STDOUT:     %.loc17: <error> = field_decl x, element0 [template]
 // CHECK:STDOUT:     %complete_type: <witness> = complete_type_witness <error> [template = <error>]
 // CHECK:STDOUT:     complete_type_witness = %complete_type
 // CHECK:STDOUT:   }
diff --git a/toolchain/check/testdata/class/generic/member_access.carbon b/toolchain/check/testdata/class/generic/member_access.carbon
index b5ccabd39fe0..f902bf4019bc 100644
--- a/toolchain/check/testdata/class/generic/member_access.carbon
+++ b/toolchain/check/testdata/class/generic/member_access.carbon
@@ -39,12 +39,13 @@ class Class(T:! type) {
 }
 
 fn StaticMemberFunctionCall(T:! type) -> Class(T) {
-  // CHECK:STDERR: fail_todo_static_member_fn_call.carbon:[[@LINE+6]]:3: error: cannot implicitly convert from `Class(T)` to `Class(T)` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_todo_static_member_fn_call.carbon:[[@LINE+7]]:3: error: cannot implicitly convert from `Class(T)` to `Class(T)` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   return Class(T).Make();
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~~~~~
-  // CHECK:STDERR: fail_todo_static_member_fn_call.carbon:[[@LINE+3]]:3: note: type `Class(T)` does not implement interface `Core.ImplicitAs(Class(T))` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR: fail_todo_static_member_fn_call.carbon:[[@LINE+4]]:3: note: type `Class(T)` does not implement interface `Core.ImplicitAs(Class(T))` [MissingImplInMemberAccessNote]
   // CHECK:STDERR:   return Class(T).Make();
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   return Class(T).Make();
 }
 
@@ -494,24 +495,24 @@ fn StaticMemberFunctionCall(T:! type) -> Class(T) {
 // CHECK:STDOUT:   %Class.loc8_49.2: type = class_type @Class, @Class(%T.loc8_29.2) [symbolic = %Class.loc8_49.2 (constants.%Class)]
 // CHECK:STDOUT:
 // CHECK:STDOUT: !definition:
-// CHECK:STDOUT:   %require_complete.loc15_18: <witness> = require_complete_type @StaticMemberFunctionCall.%Class.loc8_49.2 (%Class) [symbolic = %require_complete.loc15_18 (constants.%require_complete.4f8)]
+// CHECK:STDOUT:   %require_complete.loc16_18: <witness> = require_complete_type @StaticMemberFunctionCall.%Class.loc8_49.2 (%Class) [symbolic = %require_complete.loc16_18 (constants.%require_complete.4f8)]
 // CHECK:STDOUT:   %Make.type: type = fn_type @Make, @Class(%T.loc8_29.2) [symbolic = %Make.type (constants.%Make.type)]
 // CHECK:STDOUT:   %Make: @StaticMemberFunctionCall.%Make.type (%Make.type) = struct_value () [symbolic = %Make (constants.%Make)]
-// CHECK:STDOUT:   %Make.specific_fn.loc15_18.2: <specific function> = specific_function %Make, @Make(%T.loc8_29.2) [symbolic = %Make.specific_fn.loc15_18.2 (constants.%Make.specific_fn)]
+// CHECK:STDOUT:   %Make.specific_fn.loc16_18.2: <specific function> = specific_function %Make, @Make(%T.loc8_29.2) [symbolic = %Make.specific_fn.loc16_18.2 (constants.%Make.specific_fn)]
 // CHECK:STDOUT:   %ImplicitAs.type: type = facet_type <@ImplicitAs, @ImplicitAs(%Class.loc8_49.2)> [symbolic = %ImplicitAs.type (constants.%ImplicitAs.type.53b)]
-// CHECK:STDOUT:   %require_complete.loc15_25: <witness> = require_complete_type @StaticMemberFunctionCall.%ImplicitAs.type (%ImplicitAs.type.53b) [symbolic = %require_complete.loc15_25 (constants.%require_complete.d81)]
+// CHECK:STDOUT:   %require_complete.loc16_25: <witness> = require_complete_type @StaticMemberFunctionCall.%ImplicitAs.type (%ImplicitAs.type.53b) [symbolic = %require_complete.loc16_25 (constants.%require_complete.d81)]
 // CHECK:STDOUT:
 // CHECK:STDOUT:   fn(%T.param_patt: type) -> %return.param_patt: @StaticMemberFunctionCall.%Class.loc8_49.2 (%Class) {
 // CHECK:STDOUT:   !entry:
-// CHECK:STDOUT:     %Class.ref.loc15: %Class.type = name_ref Class, file.%Class.decl [template = constants.%Class.generic]
-// CHECK:STDOUT:     %T.ref.loc15: type = name_ref T, %T.loc8_29.1 [symbolic = %T.loc8_29.2 (constants.%T)]
-// CHECK:STDOUT:     %Class.loc15: type = class_type @Class, @Class(constants.%T) [symbolic = %Class.loc8_49.2 (constants.%Class)]
-// CHECK:STDOUT:     %.loc15_18: @StaticMemberFunctionCall.%Make.type (%Make.type) = specific_constant @Class.%Make.decl, @Class(constants.%T) [symbolic = %Make (constants.%Make)]
-// CHECK:STDOUT:     %Make.ref: @StaticMemberFunctionCall.%Make.type (%Make.type) = name_ref Make, %.loc15_18 [symbolic = %Make (constants.%Make)]
-// CHECK:STDOUT:     %Make.specific_fn.loc15_18.1: <specific function> = specific_function %Make.ref, @Make(constants.%T) [symbolic = %Make.specific_fn.loc15_18.2 (constants.%Make.specific_fn)]
-// CHECK:STDOUT:     %.loc15_24: ref @StaticMemberFunctionCall.%Class.loc8_49.2 (%Class) = temporary_storage
-// CHECK:STDOUT:     %Make.call: init @StaticMemberFunctionCall.%Class.loc8_49.2 (%Class) = call %Make.specific_fn.loc15_18.1() to %.loc15_24
-// CHECK:STDOUT:     %.loc15_25: @StaticMemberFunctionCall.%Class.loc8_49.2 (%Class) = converted %Make.call, <error> [template = <error>]
+// CHECK:STDOUT:     %Class.ref.loc16: %Class.type = name_ref Class, file.%Class.decl [template = constants.%Class.generic]
+// CHECK:STDOUT:     %T.ref.loc16: type = name_ref T, %T.loc8_29.1 [symbolic = %T.loc8_29.2 (constants.%T)]
+// CHECK:STDOUT:     %Class.loc16: type = class_type @Class, @Class(constants.%T) [symbolic = %Class.loc8_49.2 (constants.%Class)]
+// CHECK:STDOUT:     %.loc16_18: @StaticMemberFunctionCall.%Make.type (%Make.type) = specific_constant @Class.%Make.decl, @Class(constants.%T) [symbolic = %Make (constants.%Make)]
+// CHECK:STDOUT:     %Make.ref: @StaticMemberFunctionCall.%Make.type (%Make.type) = name_ref Make, %.loc16_18 [symbolic = %Make (constants.%Make)]
+// CHECK:STDOUT:     %Make.specific_fn.loc16_18.1: <specific function> = specific_function %Make.ref, @Make(constants.%T) [symbolic = %Make.specific_fn.loc16_18.2 (constants.%Make.specific_fn)]
+// CHECK:STDOUT:     %.loc16_24: ref @StaticMemberFunctionCall.%Class.loc8_49.2 (%Class) = temporary_storage
+// CHECK:STDOUT:     %Make.call: init @StaticMemberFunctionCall.%Class.loc8_49.2 (%Class) = call %Make.specific_fn.loc16_18.1() to %.loc16_24
+// CHECK:STDOUT:     %.loc16_25: @StaticMemberFunctionCall.%Class.loc8_49.2 (%Class) = converted %Make.call, <error> [template = <error>]
 // CHECK:STDOUT:     return <error> to %return
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/class/generic/member_inline.carbon b/toolchain/check/testdata/class/generic/member_inline.carbon
index f39bc32dbd8e..cb54ec4f4e89 100644
--- a/toolchain/check/testdata/class/generic/member_inline.carbon
+++ b/toolchain/check/testdata/class/generic/member_inline.carbon
@@ -30,9 +30,10 @@ library "fail_member_inline.carbon";
 
 class C(T:! type) {
   fn F() {
-    // CHECK:STDERR: fail_member_inline.carbon:[[@LINE+3]]:5: error: expression cannot be used as a value [UseOfNonExprAsValue]
+    // CHECK:STDERR: fail_member_inline.carbon:[[@LINE+4]]:5: error: expression cannot be used as a value [UseOfNonExprAsValue]
     // CHECK:STDERR:     data;
     // CHECK:STDERR:     ^~~~
+    // CHECK:STDERR:
     data;
   }
   var data: {};
@@ -241,7 +242,7 @@ class C(T:! type) {
 // CHECK:STDOUT:
 // CHECK:STDOUT:   class {
 // CHECK:STDOUT:     %F.decl: @C.%F.type (%F.type) = fn_decl @F [symbolic = @C.%F (constants.%F)] {} {}
-// CHECK:STDOUT:     %.loc11: @C.%C.elem (%C.elem) = field_decl data, element0 [template]
+// CHECK:STDOUT:     %.loc12: @C.%C.elem (%C.elem) = field_decl data, element0 [template]
 // CHECK:STDOUT:     %complete_type: <witness> = complete_type_witness %struct_type.data [template = constants.%complete_type]
 // CHECK:STDOUT:     complete_type_witness = %complete_type
 // CHECK:STDOUT:   }
@@ -255,7 +256,7 @@ class C(T:! type) {
 // CHECK:STDOUT:
 // CHECK:STDOUT:   fn() {
 // CHECK:STDOUT:   !entry:
-// CHECK:STDOUT:     %data.ref: @F.%C.elem (%C.elem) = name_ref data, @C.%.loc11 [template = @C.%.loc11]
+// CHECK:STDOUT:     %data.ref: @F.%C.elem (%C.elem) = name_ref data, @C.%.loc12 [template = @C.%.loc12]
 // CHECK:STDOUT:     return
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/class/generic/member_lookup.carbon b/toolchain/check/testdata/class/generic/member_lookup.carbon
index 77bc60824460..fdc5abda45b3 100644
--- a/toolchain/check/testdata/class/generic/member_lookup.carbon
+++ b/toolchain/check/testdata/class/generic/member_lookup.carbon
@@ -63,9 +63,10 @@ fn AccessMissingDerived[T:! type](x: Derived(T)) -> T {
 }
 
 fn AccessMissingConcrete(x: Derived(i32)) -> i32 {
-  // CHECK:STDERR: fail_no_member.carbon:[[@LINE+3]]:10: error: member name `nonesuch` not found in `Derived(i32)` [MemberNameNotFoundInScope]
+  // CHECK:STDERR: fail_no_member.carbon:[[@LINE+4]]:10: error: member name `nonesuch` not found in `Derived(i32)` [MemberNameNotFoundInScope]
   // CHECK:STDERR:   return x.nonesuch;
   // CHECK:STDERR:          ^~~~~~~~~~
+  // CHECK:STDERR:
   return x.nonesuch;
 }
 
diff --git a/toolchain/check/testdata/class/generic/member_out_of_line.carbon b/toolchain/check/testdata/class/generic/member_out_of_line.carbon
index 945e38e5369f..c2b7c2b40187 100644
--- a/toolchain/check/testdata/class/generic/member_out_of_line.carbon
+++ b/toolchain/check/testdata/class/generic/member_out_of_line.carbon
@@ -97,12 +97,13 @@ class Generic(T:! type) {
   fn WrongType();
 }
 
-// CHECK:STDERR: fail_mismatched_wrong_arg_type.carbon:[[@LINE+6]]:12: error: type `()` of parameter 1 in redeclaration differs from previous parameter type `type` [RedeclParamDiffersType]
+// CHECK:STDERR: fail_mismatched_wrong_arg_type.carbon:[[@LINE+7]]:12: error: type `()` of parameter 1 in redeclaration differs from previous parameter type `type` [RedeclParamDiffersType]
 // CHECK:STDERR: fn Generic(T:! ()).WrongType() {}
 // CHECK:STDERR:            ^~~~~~
 // CHECK:STDERR: fail_mismatched_wrong_arg_type.carbon:[[@LINE-7]]:15: note: previous declaration's corresponding parameter here [RedeclParamPrevious]
 // CHECK:STDERR: class Generic(T:! type) {
 // CHECK:STDERR:               ^~~~~~~~
+// CHECK:STDERR:
 fn Generic(T:! ()).WrongType() {}
 
 // CHECK:STDOUT: --- basic.carbon
@@ -719,11 +720,11 @@ fn Generic(T:! ()).WrongType() {}
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %.decl: %.type = fn_decl @.1 [template = constants.%.d85] {} {
 // CHECK:STDOUT:     %T.param: %empty_tuple.type = value_param runtime_param<invalid>
-// CHECK:STDOUT:     %.loc14_17.1: type = splice_block %.loc14_17.3 [template = constants.%empty_tuple.type] {
-// CHECK:STDOUT:       %.loc14_17.2: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:       %.loc14_17.3: type = converted %.loc14_17.2, constants.%empty_tuple.type [template = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %.loc15_17.1: type = splice_block %.loc15_17.3 [template = constants.%empty_tuple.type] {
+// CHECK:STDOUT:       %.loc15_17.2: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:       %.loc15_17.3: type = converted %.loc15_17.2, constants.%empty_tuple.type [template = constants.%empty_tuple.type]
 // CHECK:STDOUT:     }
-// CHECK:STDOUT:     %T.loc14_12.1: %empty_tuple.type = bind_symbolic_name T, 0, %T.param [symbolic = %T.loc14_12.2 (constants.%T.7a6)]
+// CHECK:STDOUT:     %T.loc15_12.1: %empty_tuple.type = bind_symbolic_name T, 0, %T.param [symbolic = %T.loc15_12.2 (constants.%T.7a6)]
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -747,8 +748,8 @@ fn Generic(T:! ()).WrongType() {}
 // CHECK:STDOUT:   fn();
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: generic fn @.1(%T.loc14_12.1: %empty_tuple.type) {
-// CHECK:STDOUT:   %T.loc14_12.2: %empty_tuple.type = bind_symbolic_name T, 0 [symbolic = %T.loc14_12.2 (constants.%T.7a6)]
+// CHECK:STDOUT: generic fn @.1(%T.loc15_12.1: %empty_tuple.type) {
+// CHECK:STDOUT:   %T.loc15_12.2: %empty_tuple.type = bind_symbolic_name T, 0 [symbolic = %T.loc15_12.2 (constants.%T.7a6)]
 // CHECK:STDOUT:   %T.patt: %empty_tuple.type = symbolic_binding_pattern T, 0 [symbolic = %T.patt (constants.%T.patt.e60)]
 // CHECK:STDOUT:
 // CHECK:STDOUT: !definition:
@@ -769,7 +770,7 @@ fn Generic(T:! ()).WrongType() {}
 // CHECK:STDOUT: specific @Generic(%T.loc4_15.2) {}
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @.1(constants.%T.7a6) {
-// CHECK:STDOUT:   %T.loc14_12.2 => constants.%T.7a6
+// CHECK:STDOUT:   %T.loc15_12.2 => constants.%T.7a6
 // CHECK:STDOUT:   %T.patt => constants.%T.7a6
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/generic/redeclare.carbon b/toolchain/check/testdata/class/generic/redeclare.carbon
index cbb2a8acb92d..e2958dedece1 100644
--- a/toolchain/check/testdata/class/generic/redeclare.carbon
+++ b/toolchain/check/testdata/class/generic/redeclare.carbon
@@ -78,12 +78,13 @@ class D(T:! i32) {}
 library "[[@TEST_NAME]]";
 
 class E(T:! type);
-// CHECK:STDERR: fail_mismatch_param_name.carbon:[[@LINE+6]]:9: error: redeclaration differs at parameter 1 [RedeclParamDiffers]
+// CHECK:STDERR: fail_mismatch_param_name.carbon:[[@LINE+7]]:9: error: redeclaration differs at parameter 1 [RedeclParamDiffers]
 // CHECK:STDERR: class E(U:! type) {}
 // CHECK:STDERR:         ^~~~~~~~
 // CHECK:STDERR: fail_mismatch_param_name.carbon:[[@LINE-4]]:9: note: previous declaration's corresponding parameter here [RedeclParamPrevious]
 // CHECK:STDERR: class E(T:! type);
 // CHECK:STDERR:         ^~~~~~~~
+// CHECK:STDERR:
 class E(U:! type) {}
 
 // CHECK:STDOUT: --- valid.carbon
@@ -492,11 +493,11 @@ class E(U:! type) {}
 // CHECK:STDOUT:     %T.loc4_9.1: type = bind_symbolic_name T, 0, %T.param [symbolic = %T.loc4_9.2 (constants.%T)]
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %.decl: %.type = class_decl @.1 [template = constants.%.generic] {
-// CHECK:STDOUT:     %U.patt.loc11_9.1: type = symbolic_binding_pattern U, 0 [symbolic = %U.patt.loc11_9.2 (constants.%U.patt)]
-// CHECK:STDOUT:     %U.param_patt: type = value_param_pattern %U.patt.loc11_9.1, runtime_param<invalid> [symbolic = %U.patt.loc11_9.2 (constants.%U.patt)]
+// CHECK:STDOUT:     %U.patt.loc12_9.1: type = symbolic_binding_pattern U, 0 [symbolic = %U.patt.loc12_9.2 (constants.%U.patt)]
+// CHECK:STDOUT:     %U.param_patt: type = value_param_pattern %U.patt.loc12_9.1, runtime_param<invalid> [symbolic = %U.patt.loc12_9.2 (constants.%U.patt)]
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %U.param: type = value_param runtime_param<invalid>
-// CHECK:STDOUT:     %U.loc11_9.1: type = bind_symbolic_name U, 0, %U.param [symbolic = %U.loc11_9.2 (constants.%U)]
+// CHECK:STDOUT:     %U.loc12_9.1: type = bind_symbolic_name U, 0, %U.param [symbolic = %U.loc12_9.2 (constants.%U)]
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -507,9 +508,9 @@ class E(U:! type) {}
 // CHECK:STDOUT:   class;
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: generic class @.1(%U.loc11_9.1: type) {
-// CHECK:STDOUT:   %U.loc11_9.2: type = bind_symbolic_name U, 0 [symbolic = %U.loc11_9.2 (constants.%U)]
-// CHECK:STDOUT:   %U.patt.loc11_9.2: type = symbolic_binding_pattern U, 0 [symbolic = %U.patt.loc11_9.2 (constants.%U.patt)]
+// CHECK:STDOUT: generic class @.1(%U.loc12_9.1: type) {
+// CHECK:STDOUT:   %U.loc12_9.2: type = bind_symbolic_name U, 0 [symbolic = %U.loc12_9.2 (constants.%U)]
+// CHECK:STDOUT:   %U.patt.loc12_9.2: type = symbolic_binding_pattern U, 0 [symbolic = %U.patt.loc12_9.2 (constants.%U.patt)]
 // CHECK:STDOUT:
 // CHECK:STDOUT: !definition:
 // CHECK:STDOUT:
@@ -525,7 +526,7 @@ class E(U:! type) {}
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @.1(constants.%U) {
-// CHECK:STDOUT:   %U.loc11_9.2 => constants.%U
-// CHECK:STDOUT:   %U.patt.loc11_9.2 => constants.%U
+// CHECK:STDOUT:   %U.loc12_9.2 => constants.%U
+// CHECK:STDOUT:   %U.patt.loc12_9.2 => constants.%U
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/generic/stringify.carbon b/toolchain/check/testdata/class/generic/stringify.carbon
index 47b3efdad08e..b07a7af503c8 100644
--- a/toolchain/check/testdata/class/generic/stringify.carbon
+++ b/toolchain/check/testdata/class/generic/stringify.carbon
@@ -72,19 +72,20 @@ class D {
 
 class E(F:! D) {}
 
-// CHECK:STDERR: fail_class_param.carbon:[[@LINE+13]]:8: error: argument for generic parameter is not a compile-time constant [CompTimeArgumentNotConstant]
+// CHECK:STDERR: fail_class_param.carbon:[[@LINE+14]]:8: error: argument for generic parameter is not a compile-time constant [CompTimeArgumentNotConstant]
 // CHECK:STDERR: var g: E({.a = 1, .b = 2}) = {} as E({.a = 3, .b = 4} as D);
 // CHECK:STDERR:        ^~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_class_param.carbon:[[@LINE-5]]:9: note: initializing generic parameter `F` declared here [InitializingGenericParam]
 // CHECK:STDERR: class E(F:! D) {}
 // CHECK:STDERR:         ^
 // CHECK:STDERR:
-// CHECK:STDERR: fail_class_param.carbon:[[@LINE+6]]:36: error: argument for generic parameter is not a compile-time constant [CompTimeArgumentNotConstant]
+// CHECK:STDERR: fail_class_param.carbon:[[@LINE+7]]:36: error: argument for generic parameter is not a compile-time constant [CompTimeArgumentNotConstant]
 // CHECK:STDERR: var g: E({.a = 1, .b = 2}) = {} as E({.a = 3, .b = 4} as D);
 // CHECK:STDERR:                                    ^~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_class_param.carbon:[[@LINE-12]]:9: note: initializing generic parameter `F` declared here [InitializingGenericParam]
 // CHECK:STDERR: class E(F:! D) {}
 // CHECK:STDERR:         ^
+// CHECK:STDERR:
 var g: E({.a = 1, .b = 2}) = {} as E({.a = 3, .b = 4} as D);
 
 // CHECK:STDOUT: --- fail_empty_params.carbon
@@ -425,31 +426,31 @@ var g: E({.a = 1, .b = 2}) = {} as E({.a = 3, .b = 4} as D);
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %.loc24_31: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %.loc25_31: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:   %E.ref: %E.type = name_ref E, file.%E.decl [template = constants.%E.generic]
 // CHECK:STDOUT:   %int_3: Core.IntLiteral = int_value 3 [template = constants.%int_3.1ba]
 // CHECK:STDOUT:   %int_4: Core.IntLiteral = int_value 4 [template = constants.%int_4.0c1]
-// CHECK:STDOUT:   %.loc24_53.1: %struct_type.a.b.cfd = struct_literal (%int_3, %int_4)
+// CHECK:STDOUT:   %.loc25_53.1: %struct_type.a.b.cfd = struct_literal (%int_3, %int_4)
 // CHECK:STDOUT:   %D.ref: type = name_ref D, file.%D.decl [template = constants.%D]
-// CHECK:STDOUT:   %impl.elem0.loc24_53.1: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
-// CHECK:STDOUT:   %Convert.bound.loc24_53.1: <bound method> = bound_method %int_3, %impl.elem0.loc24_53.1 [template = constants.%Convert.bound.b30]
-// CHECK:STDOUT:   %Convert.specific_fn.loc24_53.1: <specific function> = specific_function %Convert.bound.loc24_53.1, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.b42]
-// CHECK:STDOUT:   %int.convert_checked.loc24_53.1: init %i32 = call %Convert.specific_fn.loc24_53.1(%int_3) [template = constants.%int_3.822]
-// CHECK:STDOUT:   %.loc24_53.2: init %i32 = converted %int_3, %int.convert_checked.loc24_53.1 [template = constants.%int_3.822]
-// CHECK:STDOUT:   %.loc24_53.3: ref %D = temporary_storage
-// CHECK:STDOUT:   %.loc24_53.4: ref %i32 = class_element_access %.loc24_53.3, element0
-// CHECK:STDOUT:   %.loc24_53.5: init %i32 = initialize_from %.loc24_53.2 to %.loc24_53.4 [template = constants.%int_3.822]
-// CHECK:STDOUT:   %impl.elem0.loc24_53.2: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
-// CHECK:STDOUT:   %Convert.bound.loc24_53.2: <bound method> = bound_method %int_4, %impl.elem0.loc24_53.2 [template = constants.%Convert.bound.ac3]
-// CHECK:STDOUT:   %Convert.specific_fn.loc24_53.2: <specific function> = specific_function %Convert.bound.loc24_53.2, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.450]
-// CHECK:STDOUT:   %int.convert_checked.loc24_53.2: init %i32 = call %Convert.specific_fn.loc24_53.2(%int_4) [template = constants.%int_4.940]
-// CHECK:STDOUT:   %.loc24_53.6: init %i32 = converted %int_4, %int.convert_checked.loc24_53.2 [template = constants.%int_4.940]
-// CHECK:STDOUT:   %.loc24_53.7: ref %i32 = class_element_access %.loc24_53.3, element1
-// CHECK:STDOUT:   %.loc24_53.8: init %i32 = initialize_from %.loc24_53.6 to %.loc24_53.7 [template = constants.%int_4.940]
-// CHECK:STDOUT:   %.loc24_53.9: init %D = class_init (%.loc24_53.5, %.loc24_53.8), %.loc24_53.3 [template = constants.%D.val.835]
-// CHECK:STDOUT:   %.loc24_53.10: ref %D = temporary %.loc24_53.3, %.loc24_53.9
-// CHECK:STDOUT:   %.loc24_55.1: ref %D = converted %.loc24_53.1, %.loc24_53.10
-// CHECK:STDOUT:   %.loc24_55.2: %D = bind_value %.loc24_55.1
+// CHECK:STDOUT:   %impl.elem0.loc25_53.1: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
+// CHECK:STDOUT:   %Convert.bound.loc25_53.1: <bound method> = bound_method %int_3, %impl.elem0.loc25_53.1 [template = constants.%Convert.bound.b30]
+// CHECK:STDOUT:   %Convert.specific_fn.loc25_53.1: <specific function> = specific_function %Convert.bound.loc25_53.1, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.b42]
+// CHECK:STDOUT:   %int.convert_checked.loc25_53.1: init %i32 = call %Convert.specific_fn.loc25_53.1(%int_3) [template = constants.%int_3.822]
+// CHECK:STDOUT:   %.loc25_53.2: init %i32 = converted %int_3, %int.convert_checked.loc25_53.1 [template = constants.%int_3.822]
+// CHECK:STDOUT:   %.loc25_53.3: ref %D = temporary_storage
+// CHECK:STDOUT:   %.loc25_53.4: ref %i32 = class_element_access %.loc25_53.3, element0
+// CHECK:STDOUT:   %.loc25_53.5: init %i32 = initialize_from %.loc25_53.2 to %.loc25_53.4 [template = constants.%int_3.822]
+// CHECK:STDOUT:   %impl.elem0.loc25_53.2: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
+// CHECK:STDOUT:   %Convert.bound.loc25_53.2: <bound method> = bound_method %int_4, %impl.elem0.loc25_53.2 [template = constants.%Convert.bound.ac3]
+// CHECK:STDOUT:   %Convert.specific_fn.loc25_53.2: <specific function> = specific_function %Convert.bound.loc25_53.2, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.450]
+// CHECK:STDOUT:   %int.convert_checked.loc25_53.2: init %i32 = call %Convert.specific_fn.loc25_53.2(%int_4) [template = constants.%int_4.940]
+// CHECK:STDOUT:   %.loc25_53.6: init %i32 = converted %int_4, %int.convert_checked.loc25_53.2 [template = constants.%int_4.940]
+// CHECK:STDOUT:   %.loc25_53.7: ref %i32 = class_element_access %.loc25_53.3, element1
+// CHECK:STDOUT:   %.loc25_53.8: init %i32 = initialize_from %.loc25_53.6 to %.loc25_53.7 [template = constants.%int_4.940]
+// CHECK:STDOUT:   %.loc25_53.9: init %D = class_init (%.loc25_53.5, %.loc25_53.8), %.loc25_53.3 [template = constants.%D.val.835]
+// CHECK:STDOUT:   %.loc25_53.10: ref %D = temporary %.loc25_53.3, %.loc25_53.9
+// CHECK:STDOUT:   %.loc25_55.1: ref %D = converted %.loc25_53.1, %.loc25_53.10
+// CHECK:STDOUT:   %.loc25_55.2: %D = bind_value %.loc25_55.1
 // CHECK:STDOUT:   assign file.%g.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/class/inheritance_access.carbon b/toolchain/check/testdata/class/inheritance_access.carbon
index aaad8861a00f..c965aed3e90d 100644
--- a/toolchain/check/testdata/class/inheritance_access.carbon
+++ b/toolchain/check/testdata/class/inheritance_access.carbon
@@ -200,12 +200,13 @@ base class A {
 class B {
   extend base: A;
   fn F[self: Self]() {
-    // CHECK:STDERR: fail_compound_member_access.carbon:[[@LINE+6]]:11: error: cannot access private member `x` of type `A` [ClassInvalidMemberAccess]
+    // CHECK:STDERR: fail_compound_member_access.carbon:[[@LINE+7]]:11: error: cannot access private member `x` of type `A` [ClassInvalidMemberAccess]
     // CHECK:STDERR:     self.(A.x);
     // CHECK:STDERR:           ^~~
     // CHECK:STDERR: fail_compound_member_access.carbon:[[@LINE-9]]:15: note: declared here [ClassMemberDeclaration]
     // CHECK:STDERR:   private var x: i32;
     // CHECK:STDERR:               ^~~~~~
+    // CHECK:STDERR:
     self.(A.x);
   }
 }
diff --git a/toolchain/check/testdata/class/no_prelude/extern.carbon b/toolchain/check/testdata/class/no_prelude/extern.carbon
index 73e4c56a1b6f..ebdb64529443 100644
--- a/toolchain/check/testdata/class/no_prelude/extern.carbon
+++ b/toolchain/check/testdata/class/no_prelude/extern.carbon
@@ -272,13 +272,14 @@ library "[[@TEST_NAME]]";
 
 import library "def";
 
-// CHECK:STDERR: fail_extern_decl_after_import_def.carbon:[[@LINE+7]]:1: error: redeclarations of `class C` must match use of `extern` [RedeclExternMismatch]
+// CHECK:STDERR: fail_extern_decl_after_import_def.carbon:[[@LINE+8]]:1: error: redeclarations of `class C` must match use of `extern` [RedeclExternMismatch]
 // CHECK:STDERR: extern class C;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_extern_decl_after_import_def.carbon:[[@LINE-5]]:1: in import [InImport]
 // CHECK:STDERR: def.carbon:4:1: note: previously declared here [RedeclPrevDecl]
 // CHECK:STDERR: class C {}
 // CHECK:STDERR: ^~~~~~~~~
+// CHECK:STDERR:
 extern class C;
 
 // CHECK:STDOUT: --- decl.carbon
diff --git a/toolchain/check/testdata/class/no_prelude/extern_library.carbon b/toolchain/check/testdata/class/no_prelude/extern_library.carbon
index 38b12724e8de..d0e314b973a4 100644
--- a/toolchain/check/testdata/class/no_prelude/extern_library.carbon
+++ b/toolchain/check/testdata/class/no_prelude/extern_library.carbon
@@ -10,9 +10,10 @@
 
 // --- fail_todo.carbon
 
-// CHECK:STDERR: fail_todo.carbon:[[@LINE+3]]:1: error: semantics TODO: `extern library` [SemanticsTodo]
+// CHECK:STDERR: fail_todo.carbon:[[@LINE+4]]:1: error: semantics TODO: `extern library` [SemanticsTodo]
 // CHECK:STDERR: extern library "foo" class C;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 extern library "foo" class C;
 
 // CHECK:STDOUT: --- fail_todo.carbon
diff --git a/toolchain/check/testdata/class/no_prelude/generic_vs_params.carbon b/toolchain/check/testdata/class/no_prelude/generic_vs_params.carbon
index fb97e365aef1..24a76bfdbc86 100644
--- a/toolchain/check/testdata/class/no_prelude/generic_vs_params.carbon
+++ b/toolchain/check/testdata/class/no_prelude/generic_vs_params.carbon
@@ -43,9 +43,10 @@ class A[T: type]() {}
 
 library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_non_generic_params.carbon:[[@LINE+3]]:9: error: parameters of generic types must be constant [GenericParamMustBeConstant]
+// CHECK:STDERR: fail_non_generic_params.carbon:[[@LINE+4]]:9: error: parameters of generic types must be constant [GenericParamMustBeConstant]
 // CHECK:STDERR: class A(T: type) {}
 // CHECK:STDERR:         ^~~~~~~
+// CHECK:STDERR:
 class A(T: type) {}
 
 // This is testing a use of the invalid type.
@@ -306,11 +307,11 @@ fn F(T:! type) {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %A.decl: %A.type = class_decl @A [template = constants.%A.generic] {} {}
 // CHECK:STDOUT:   %F.decl: %F.type = fn_decl @F [template = constants.%F] {
-// CHECK:STDOUT:     %T.patt.loc10_6.1: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc10_6.2 (constants.%T.patt)]
-// CHECK:STDOUT:     %T.param_patt: type = value_param_pattern %T.patt.loc10_6.1, runtime_param<invalid> [symbolic = %T.patt.loc10_6.2 (constants.%T.patt)]
+// CHECK:STDOUT:     %T.patt.loc11_6.1: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc11_6.2 (constants.%T.patt)]
+// CHECK:STDOUT:     %T.param_patt: type = value_param_pattern %T.patt.loc11_6.1, runtime_param<invalid> [symbolic = %T.patt.loc11_6.2 (constants.%T.patt)]
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %T.param: type = value_param runtime_param<invalid>
-// CHECK:STDOUT:     %T.loc10_6.1: type = bind_symbolic_name T, 0, %T.param [symbolic = %T.loc10_6.2 (constants.%T)]
+// CHECK:STDOUT:     %T.loc11_6.1: type = bind_symbolic_name T, 0, %T.param [symbolic = %T.loc11_6.2 (constants.%T)]
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -319,23 +320,23 @@ fn F(T:! type) {
 // CHECK:STDOUT:   complete_type_witness = %complete_type
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: generic fn @F(%T.loc10_6.1: type) {
-// CHECK:STDOUT:   %T.loc10_6.2: type = bind_symbolic_name T, 0 [symbolic = %T.loc10_6.2 (constants.%T)]
-// CHECK:STDOUT:   %T.patt.loc10_6.2: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc10_6.2 (constants.%T.patt)]
+// CHECK:STDOUT: generic fn @F(%T.loc11_6.1: type) {
+// CHECK:STDOUT:   %T.loc11_6.2: type = bind_symbolic_name T, 0 [symbolic = %T.loc11_6.2 (constants.%T)]
+// CHECK:STDOUT:   %T.patt.loc11_6.2: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc11_6.2 (constants.%T.patt)]
 // CHECK:STDOUT:
 // CHECK:STDOUT: !definition:
 // CHECK:STDOUT:
 // CHECK:STDOUT:   fn(%T.param_patt: type) {
 // CHECK:STDOUT:   !entry:
 // CHECK:STDOUT:     %A.ref: %A.type = name_ref A, file.%A.decl [template = constants.%A.generic]
-// CHECK:STDOUT:     %T.ref: type = name_ref T, %T.loc10_6.1 [symbolic = %T.loc10_6.2 (constants.%T)]
+// CHECK:STDOUT:     %T.ref: type = name_ref T, %T.loc11_6.1 [symbolic = %T.loc11_6.2 (constants.%T)]
 // CHECK:STDOUT:     %A: type = class_type @A [template = constants.%A]
 // CHECK:STDOUT:     return
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @F(constants.%T) {
-// CHECK:STDOUT:   %T.loc10_6.2 => constants.%T
-// CHECK:STDOUT:   %T.patt.loc10_6.2 => constants.%T
+// CHECK:STDOUT:   %T.loc11_6.2 => constants.%T
+// CHECK:STDOUT:   %T.patt.loc11_6.2 => constants.%T
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/no_prelude/implicit_import.carbon b/toolchain/check/testdata/class/no_prelude/implicit_import.carbon
index 3040acd6d34f..7fe0a52fd775 100644
--- a/toolchain/check/testdata/class/no_prelude/implicit_import.carbon
+++ b/toolchain/check/testdata/class/no_prelude/implicit_import.carbon
@@ -71,13 +71,14 @@ alias B = C;
 
 impl library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_def_alias.impl.carbon:[[@LINE+7]]:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
+// CHECK:STDERR: fail_def_alias.impl.carbon:[[@LINE+8]]:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
 // CHECK:STDERR: class B {}
 // CHECK:STDERR: ^~~~~~~~~
 // CHECK:STDERR: fail_def_alias.impl.carbon:[[@LINE-5]]:6: in import [InImport]
 // CHECK:STDERR: def_alias.carbon:5:7: note: name is previously declared here [NameDeclPrevious]
 // CHECK:STDERR: alias B = C;
 // CHECK:STDERR:       ^
+// CHECK:STDERR:
 class B {}
 
 // CHECK:STDOUT: --- basic.carbon
diff --git a/toolchain/check/testdata/class/no_prelude/import_access.carbon b/toolchain/check/testdata/class/no_prelude/import_access.carbon
index 94546289d52e..d849f47119d0 100644
--- a/toolchain/check/testdata/class/no_prelude/import_access.carbon
+++ b/toolchain/check/testdata/class/no_prelude/import_access.carbon
@@ -122,9 +122,10 @@ package Other library "[[@TEST_NAME]]";
 
 import Test library "forward";
 
-// CHECK:STDERR: fail_other_forward.carbon:[[@LINE+3]]:9: error: member name `Forward` not found in `Test` [MemberNameNotFoundInScope]
+// CHECK:STDERR: fail_other_forward.carbon:[[@LINE+4]]:9: error: member name `Forward` not found in `Test` [MemberNameNotFoundInScope]
 // CHECK:STDERR: fn F(c: Test.Forward*) {}
 // CHECK:STDERR:         ^~~~~~~~~~~~
+// CHECK:STDERR:
 fn F(c: Test.Forward*) {}
 
 // --- todo_fail_private_on_redecl.carbon
@@ -469,7 +470,7 @@ private class Redecl {}
 // CHECK:STDOUT:     %c.param_patt: <error> = value_param_pattern %c.patt, runtime_param0
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %c.param: <error> = value_param runtime_param0
-// CHECK:STDOUT:     %.loc9: type = splice_block %ptr [template = <error>] {
+// CHECK:STDOUT:     %.loc10: type = splice_block %ptr [template = <error>] {
 // CHECK:STDOUT:       %Test.ref: <namespace> = name_ref Test, imports.%Test [template = imports.%Test]
 // CHECK:STDOUT:       %Forward.ref: <error> = name_ref Forward, <error> [template = <error>]
 // CHECK:STDOUT:       %ptr: type = ptr_type <error> [template = <error>]
diff --git a/toolchain/check/testdata/class/no_prelude/no_definition_in_impl_file.carbon b/toolchain/check/testdata/class/no_prelude/no_definition_in_impl_file.carbon
index 2acef044c4df..eae7928e8f08 100644
--- a/toolchain/check/testdata/class/no_prelude/no_definition_in_impl_file.carbon
+++ b/toolchain/check/testdata/class/no_prelude/no_definition_in_impl_file.carbon
@@ -66,9 +66,10 @@ library "[[@TEST_NAME]]";
 
 impl library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_decl_only_in_impl.impl.carbon:[[@LINE+3]]:1: error: no definition found for declaration in impl file [MissingDefinitionInImpl]
+// CHECK:STDERR: fail_decl_only_in_impl.impl.carbon:[[@LINE+4]]:1: error: no definition found for declaration in impl file [MissingDefinitionInImpl]
 // CHECK:STDERR: class D;
 // CHECK:STDERR: ^~~~~~~~
+// CHECK:STDERR:
 class D;
 
 // CHECK:STDOUT: --- decl_in_api_definition_in_impl.carbon
diff --git a/toolchain/check/testdata/class/no_prelude/syntactic_merge.carbon b/toolchain/check/testdata/class/no_prelude/syntactic_merge.carbon
index 73565f18a508..c2c12a0f9b05 100644
--- a/toolchain/check/testdata/class/no_prelude/syntactic_merge.carbon
+++ b/toolchain/check/testdata/class/no_prelude/syntactic_merge.carbon
@@ -169,12 +169,13 @@ base class Base {
   fn F[addr self: Self*]();
 }
 
-// CHECK:STDERR: fail_self_type.carbon:[[@LINE+6]]:22: error: redeclaration syntax differs here [RedeclParamSyntaxDiffers]
+// CHECK:STDERR: fail_self_type.carbon:[[@LINE+7]]:22: error: redeclaration syntax differs here [RedeclParamSyntaxDiffers]
 // CHECK:STDERR: fn Base.F[addr self: Base*]() {
 // CHECK:STDERR:                      ^~~~
 // CHECK:STDERR: fail_self_type.carbon:[[@LINE-6]]:19: note: comparing with previous declaration here [RedeclParamSyntaxPrevious]
 // CHECK:STDERR:   fn F[addr self: Self*]();
 // CHECK:STDERR:                   ^~~~
+// CHECK:STDERR:
 fn Base.F[addr self: Base*]() {
   (*self).a = ();
 }
@@ -1054,10 +1055,10 @@ fn Base.F[addr self: Base*]() {
 // CHECK:STDOUT:   %.decl: %.type = fn_decl @.1 [template = constants.%.ad0] {
 // CHECK:STDOUT:     %self.patt: %ptr.11f = binding_pattern self
 // CHECK:STDOUT:     %self.param_patt: %ptr.11f = value_param_pattern %self.patt, runtime_param0
-// CHECK:STDOUT:     %.loc16_11: auto = addr_pattern %self.param_patt
+// CHECK:STDOUT:     %.loc17_11: auto = addr_pattern %self.param_patt
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %self.param: %ptr.11f = value_param runtime_param0
-// CHECK:STDOUT:     %.loc16_26: type = splice_block %ptr [template = constants.%ptr.11f] {
+// CHECK:STDOUT:     %.loc17_26: type = splice_block %ptr [template = constants.%ptr.11f] {
 // CHECK:STDOUT:       %Base.ref: type = name_ref Base, file.%Base.decl [template = constants.%Base]
 // CHECK:STDOUT:       %ptr: type = ptr_type %Base [template = constants.%ptr.11f]
 // CHECK:STDOUT:     }
@@ -1088,13 +1089,13 @@ fn Base.F[addr self: Base*]() {
 // CHECK:STDOUT: fn @.1[addr %self.param_patt: %ptr.11f]() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %self.ref: %ptr.11f = name_ref self, %self
-// CHECK:STDOUT:   %.loc17_4: ref %Base = deref %self.ref
+// CHECK:STDOUT:   %.loc18_4: ref %Base = deref %self.ref
 // CHECK:STDOUT:   %a.ref: %Base.elem = name_ref a, @Base.%.loc5 [template = @Base.%.loc5]
-// CHECK:STDOUT:   %.loc17_10: ref %empty_tuple.type = class_element_access %.loc17_4, element0
-// CHECK:STDOUT:   %.loc17_16.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:   %.loc17_16.2: init %empty_tuple.type = tuple_init () to %.loc17_10 [template = constants.%empty_tuple]
-// CHECK:STDOUT:   %.loc17_13: init %empty_tuple.type = converted %.loc17_16.1, %.loc17_16.2 [template = constants.%empty_tuple]
-// CHECK:STDOUT:   assign %.loc17_10, %.loc17_13
+// CHECK:STDOUT:   %.loc18_10: ref %empty_tuple.type = class_element_access %.loc18_4, element0
+// CHECK:STDOUT:   %.loc18_16.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:   %.loc18_16.2: init %empty_tuple.type = tuple_init () to %.loc18_10 [template = constants.%empty_tuple]
+// CHECK:STDOUT:   %.loc18_13: init %empty_tuple.type = converted %.loc18_16.1, %.loc18_16.2 [template = constants.%empty_tuple]
+// CHECK:STDOUT:   assign %.loc18_10, %.loc18_13
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/self.carbon b/toolchain/check/testdata/class/self.carbon
index f6705fa2f6f4..28514f6051a0 100644
--- a/toolchain/check/testdata/class/self.carbon
+++ b/toolchain/check/testdata/class/self.carbon
@@ -32,12 +32,13 @@ fn Class.G[addr self: Self*]() -> i32 {
 library "[[@TEST_NAME]]";
 
 class Class {
-  // CHECK:STDERR: fail_return_self_value.carbon:[[@LINE+6]]:25: error: cannot implicitly convert from `Class` to `type` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_return_self_value.carbon:[[@LINE+7]]:25: error: cannot implicitly convert from `Class` to `type` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   fn F[self: Self]() -> self;
   // CHECK:STDERR:                         ^~~~
-  // CHECK:STDERR: fail_return_self_value.carbon:[[@LINE+3]]:25: note: type `Class` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR: fail_return_self_value.carbon:[[@LINE+4]]:25: note: type `Class` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
   // CHECK:STDERR:   fn F[self: Self]() -> self;
   // CHECK:STDERR:                         ^~~~
+  // CHECK:STDERR:
   fn F[self: Self]() -> self;
 }
 
@@ -198,7 +199,7 @@ class Class {
 // CHECK:STDOUT:     %return.param_patt: <error> = out_param_pattern %return.patt, runtime_param1
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %self.ref: %Class = name_ref self, %self
-// CHECK:STDOUT:     %.loc11: type = converted %self.ref, <error> [template = <error>]
+// CHECK:STDOUT:     %.loc12: type = converted %self.ref, <error> [template = <error>]
 // CHECK:STDOUT:     %self.param: %Class = value_param runtime_param0
 // CHECK:STDOUT:     %Self.ref: type = name_ref Self, constants.%Class [template = constants.%Class]
 // CHECK:STDOUT:     %self: %Class = bind_name self, %self.param
diff --git a/toolchain/check/testdata/class/syntactic_merge_literal.carbon b/toolchain/check/testdata/class/syntactic_merge_literal.carbon
index 88fb4b494511..d81a614d04fa 100644
--- a/toolchain/check/testdata/class/syntactic_merge_literal.carbon
+++ b/toolchain/check/testdata/class/syntactic_merge_literal.carbon
@@ -22,12 +22,13 @@ library "[[@TEST_NAME]]";
 
 class C(a:! i32) {}
 class D(b:! C(1000));
-// CHECK:STDERR: fail_int_mismatch.carbon:[[@LINE+6]]:15: error: redeclaration syntax differs here [RedeclParamSyntaxDiffers]
+// CHECK:STDERR: fail_int_mismatch.carbon:[[@LINE+7]]:15: error: redeclaration syntax differs here [RedeclParamSyntaxDiffers]
 // CHECK:STDERR: class D(b:! C(1_000)) {}
 // CHECK:STDERR:               ^~~~~
 // CHECK:STDERR: fail_int_mismatch.carbon:[[@LINE-4]]:15: note: comparing with previous declaration here [RedeclParamSyntaxPrevious]
 // CHECK:STDERR: class D(b:! C(1000));
 // CHECK:STDERR:               ^~~~
+// CHECK:STDERR:
 class D(b:! C(1_000)) {}
 
 // CHECK:STDOUT: --- int_match.carbon
@@ -234,22 +235,22 @@ class D(b:! C(1_000)) {}
 // CHECK:STDOUT:     %b.loc5_9.1: %C.262 = bind_symbolic_name b, 0, %b.param [symbolic = %b.loc5_9.2 (constants.%b)]
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %.decl: %.type = class_decl @.1 [template = constants.%.generic] {
-// CHECK:STDOUT:     %b.patt.loc12_9.1: %C.262 = symbolic_binding_pattern b, 0 [symbolic = %b.patt.loc12_9.2 (constants.%b.patt)]
-// CHECK:STDOUT:     %b.param_patt: %C.262 = value_param_pattern %b.patt.loc12_9.1, runtime_param<invalid> [symbolic = %b.patt.loc12_9.2 (constants.%b.patt)]
+// CHECK:STDOUT:     %b.patt.loc13_9.1: %C.262 = symbolic_binding_pattern b, 0 [symbolic = %b.patt.loc13_9.2 (constants.%b.patt)]
+// CHECK:STDOUT:     %b.param_patt: %C.262 = value_param_pattern %b.patt.loc13_9.1, runtime_param<invalid> [symbolic = %b.patt.loc13_9.2 (constants.%b.patt)]
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %b.param: %C.262 = value_param runtime_param<invalid>
-// CHECK:STDOUT:     %.loc12_20.1: type = splice_block %C [template = constants.%C.262] {
+// CHECK:STDOUT:     %.loc13_20.1: type = splice_block %C [template = constants.%C.262] {
 // CHECK:STDOUT:       %C.ref: %C.type = name_ref C, file.%C.decl [template = constants.%C.generic]
 // CHECK:STDOUT:       %int_1000: Core.IntLiteral = int_value 1000 [template = constants.%int_1000.ff9]
 // CHECK:STDOUT:       %impl.elem0: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
 // CHECK:STDOUT:       %Convert.bound: <bound method> = bound_method %int_1000, %impl.elem0 [template = constants.%Convert.bound]
 // CHECK:STDOUT:       %Convert.specific_fn: <specific function> = specific_function %Convert.bound, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn]
 // CHECK:STDOUT:       %int.convert_checked: init %i32 = call %Convert.specific_fn(%int_1000) [template = constants.%int_1000.1b6]
-// CHECK:STDOUT:       %.loc12_20.2: %i32 = value_of_initializer %int.convert_checked [template = constants.%int_1000.1b6]
-// CHECK:STDOUT:       %.loc12_20.3: %i32 = converted %int_1000, %.loc12_20.2 [template = constants.%int_1000.1b6]
+// CHECK:STDOUT:       %.loc13_20.2: %i32 = value_of_initializer %int.convert_checked [template = constants.%int_1000.1b6]
+// CHECK:STDOUT:       %.loc13_20.3: %i32 = converted %int_1000, %.loc13_20.2 [template = constants.%int_1000.1b6]
 // CHECK:STDOUT:       %C: type = class_type @C, @C(constants.%int_1000.1b6) [template = constants.%C.262]
 // CHECK:STDOUT:     }
-// CHECK:STDOUT:     %b.loc12_9.1: %C.262 = bind_symbolic_name b, 0, %b.param [symbolic = %b.loc12_9.2 (constants.%b)]
+// CHECK:STDOUT:     %b.loc13_9.1: %C.262 = bind_symbolic_name b, 0, %b.param [symbolic = %b.loc13_9.2 (constants.%b)]
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -272,9 +273,9 @@ class D(b:! C(1_000)) {}
 // CHECK:STDOUT:   class;
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: generic class @.1(%b.loc12_9.1: %C.262) {
-// CHECK:STDOUT:   %b.loc12_9.2: %C.262 = bind_symbolic_name b, 0 [symbolic = %b.loc12_9.2 (constants.%b)]
-// CHECK:STDOUT:   %b.patt.loc12_9.2: %C.262 = symbolic_binding_pattern b, 0 [symbolic = %b.patt.loc12_9.2 (constants.%b.patt)]
+// CHECK:STDOUT: generic class @.1(%b.loc13_9.1: %C.262) {
+// CHECK:STDOUT:   %b.loc13_9.2: %C.262 = bind_symbolic_name b, 0 [symbolic = %b.loc13_9.2 (constants.%b)]
+// CHECK:STDOUT:   %b.patt.loc13_9.2: %C.262 = symbolic_binding_pattern b, 0 [symbolic = %b.patt.loc13_9.2 (constants.%b.patt)]
 // CHECK:STDOUT:
 // CHECK:STDOUT: !definition:
 // CHECK:STDOUT:
@@ -300,7 +301,7 @@ class D(b:! C(1_000)) {}
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @.1(constants.%b) {
-// CHECK:STDOUT:   %b.loc12_9.2 => constants.%b
-// CHECK:STDOUT:   %b.patt.loc12_9.2 => constants.%b
+// CHECK:STDOUT:   %b.loc13_9.2 => constants.%b
+// CHECK:STDOUT:   %b.patt.loc13_9.2 => constants.%b
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/virtual_modifiers.carbon b/toolchain/check/testdata/class/virtual_modifiers.carbon
index 4f13bea31895..6974133c91ed 100644
--- a/toolchain/check/testdata/class/virtual_modifiers.carbon
+++ b/toolchain/check/testdata/class/virtual_modifiers.carbon
@@ -90,9 +90,10 @@ class C {
 package FailModifiers;
 
 class C {
-  // CHECK:STDERR: fail_modifiers.carbon:[[@LINE+3]]:3: error: impl without base class [ImplWithoutBase]
+  // CHECK:STDERR: fail_modifiers.carbon:[[@LINE+4]]:3: error: impl without base class [ImplWithoutBase]
   // CHECK:STDERR:   impl fn F();
   // CHECK:STDERR:   ^~~~~~~~~~~~
+  // CHECK:STDERR:
   impl fn F();
 }
 
@@ -555,7 +556,7 @@ class Derived {
 // CHECK:STDOUT:
 // CHECK:STDOUT: class @C {
 // CHECK:STDOUT:   %F.decl: %F.type = fn_decl @F [template = constants.%F] {} {}
-// CHECK:STDOUT:   %.loc9: <vtable> = vtable () [template = constants.%.f2b]
+// CHECK:STDOUT:   %.loc10: <vtable> = vtable () [template = constants.%.f2b]
 // CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %struct_type.vptr [template = constants.%complete_type]
 // CHECK:STDOUT:   complete_type_witness = %complete_type
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/const/collapse.carbon b/toolchain/check/testdata/const/collapse.carbon
index ca252e668789..02738f2f847f 100644
--- a/toolchain/check/testdata/const/collapse.carbon
+++ b/toolchain/check/testdata/const/collapse.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/const/collapse.carbon
 
 // OK, `const (const i32)` is the same type as `const i32`.
-// CHECK:STDERR: collapse.carbon:[[@LINE+3]]:25: warning: `const` applied repeatedly to the same type has no additional effect [RepeatedConst]
+// CHECK:STDERR: collapse.carbon:[[@LINE+4]]:25: warning: `const` applied repeatedly to the same type has no additional effect [RepeatedConst]
 // CHECK:STDERR: fn F(p: const i32**) -> const (const i32)** {
 // CHECK:STDERR:                         ^~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 fn F(p: const i32**) -> const (const i32)** {
   return p;
 }
@@ -48,19 +49,19 @@ fn F(p: const i32**) -> const (const i32)** {
 // CHECK:STDOUT:     %return.patt: %ptr.3bc = return_slot_pattern
 // CHECK:STDOUT:     %return.param_patt: %ptr.3bc = out_param_pattern %return.patt, runtime_param1
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %int_32.loc15_38: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:     %i32.loc15_38: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
-// CHECK:STDOUT:     %const.loc15_32: type = const_type %i32 [template = constants.%const]
-// CHECK:STDOUT:     %const.loc15_25: type = const_type %const [template = constants.%const]
-// CHECK:STDOUT:     %ptr.loc15_42: type = ptr_type %const [template = constants.%ptr.36b]
-// CHECK:STDOUT:     %ptr.loc15_43: type = ptr_type %ptr.36b [template = constants.%ptr.3bc]
+// CHECK:STDOUT:     %int_32.loc16_38: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:     %i32.loc16_38: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:     %const.loc16_32: type = const_type %i32 [template = constants.%const]
+// CHECK:STDOUT:     %const.loc16_25: type = const_type %const [template = constants.%const]
+// CHECK:STDOUT:     %ptr.loc16_42: type = ptr_type %const [template = constants.%ptr.36b]
+// CHECK:STDOUT:     %ptr.loc16_43: type = ptr_type %ptr.36b [template = constants.%ptr.3bc]
 // CHECK:STDOUT:     %p.param: %ptr.3bc = value_param runtime_param0
-// CHECK:STDOUT:     %.loc15: type = splice_block %ptr.loc15_19 [template = constants.%ptr.3bc] {
-// CHECK:STDOUT:       %int_32.loc15_15: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:       %i32.loc15_15: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
-// CHECK:STDOUT:       %const.loc15_9: type = const_type %i32 [template = constants.%const]
-// CHECK:STDOUT:       %ptr.loc15_18: type = ptr_type %const [template = constants.%ptr.36b]
-// CHECK:STDOUT:       %ptr.loc15_19: type = ptr_type %ptr.36b [template = constants.%ptr.3bc]
+// CHECK:STDOUT:     %.loc16: type = splice_block %ptr.loc16_19 [template = constants.%ptr.3bc] {
+// CHECK:STDOUT:       %int_32.loc16_15: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:       %i32.loc16_15: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:       %const.loc16_9: type = const_type %i32 [template = constants.%const]
+// CHECK:STDOUT:       %ptr.loc16_18: type = ptr_type %const [template = constants.%ptr.36b]
+// CHECK:STDOUT:       %ptr.loc16_19: type = ptr_type %ptr.36b [template = constants.%ptr.3bc]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %p: %ptr.3bc = bind_name p, %p.param
 // CHECK:STDOUT:     %return.param: ref %ptr.3bc = out_param runtime_param1
diff --git a/toolchain/check/testdata/const/fail_collapse.carbon b/toolchain/check/testdata/const/fail_collapse.carbon
index 570ab8ca4208..1f0a7f4b4f4e 100644
--- a/toolchain/check/testdata/const/fail_collapse.carbon
+++ b/toolchain/check/testdata/const/fail_collapse.carbon
@@ -13,12 +13,13 @@
 // CHECK:STDERR:         ^~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
 fn G(p: const (const i32)**) -> i32** {
-  // CHECK:STDERR: fail_collapse.carbon:[[@LINE+6]]:3: error: cannot implicitly convert from `const i32**` to `i32**` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_collapse.carbon:[[@LINE+7]]:3: error: cannot implicitly convert from `const i32**` to `i32**` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   return p;
   // CHECK:STDERR:   ^~~~~~~~~
-  // CHECK:STDERR: fail_collapse.carbon:[[@LINE+3]]:3: note: type `const i32**` does not implement interface `Core.ImplicitAs(i32**)` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR: fail_collapse.carbon:[[@LINE+4]]:3: note: type `const i32**` does not implement interface `Core.ImplicitAs(i32**)` [MissingImplInMemberAccessNote]
   // CHECK:STDERR:   return p;
   // CHECK:STDERR:   ^~~~~~~~~
+  // CHECK:STDERR:
   return p;
 }
 
@@ -79,7 +80,7 @@ fn G(p: const (const i32)**) -> i32** {
 // CHECK:STDOUT: fn @G(%p.param_patt: %ptr.3bc) -> %ptr.5d5 {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %p.ref: %ptr.3bc = name_ref p, %p
-// CHECK:STDOUT:   %.loc22: %ptr.5d5 = converted %p.ref, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc23: %ptr.5d5 = converted %p.ref, <error> [template = <error>]
 // CHECK:STDOUT:   return <error>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/deduce/array.carbon b/toolchain/check/testdata/deduce/array.carbon
index 7e7d8ba21c7d..d81d8a42eba3 100644
--- a/toolchain/check/testdata/deduce/array.carbon
+++ b/toolchain/check/testdata/deduce/array.carbon
@@ -111,12 +111,13 @@ fn G() -> i32 {
   // which we can't deduce through. We should decide if we want to support
   // deductions of that form. If not, it'd be nice to diagnose this situation
   // better.
-  // CHECK:STDERR: fail_bound_type_mismatch.carbon:[[@LINE+6]]:10: error: cannot deduce value for generic parameter `N` [DeductionIncomplete]
+  // CHECK:STDERR: fail_bound_type_mismatch.carbon:[[@LINE+7]]:10: error: cannot deduce value for generic parameter `N` [DeductionIncomplete]
   // CHECK:STDERR:   return F(a);
   // CHECK:STDERR:          ^~~~
   // CHECK:STDERR: fail_bound_type_mismatch.carbon:[[@LINE-12]]:1: note: while deducing parameters of generic declared here [DeductionGenericHere]
   // CHECK:STDERR: fn F[N:! i32](a: [C; N]) -> i32 { return N; }
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   return F(a);
 }
 
diff --git a/toolchain/check/testdata/deduce/int_float.carbon b/toolchain/check/testdata/deduce/int_float.carbon
index 6732102cd696..58136d7f5a9d 100644
--- a/toolchain/check/testdata/deduce/int_float.carbon
+++ b/toolchain/check/testdata/deduce/int_float.carbon
@@ -25,9 +25,10 @@ fn G(a: i64) -> Core.IntLiteral() {
 library "[[@TEST_NAME]]";
 
 // TODO: This should pass once we accept symbolic widths for Core.Float.
-// CHECK:STDERR: fail_todo_float.carbon:[[@LINE+3]]:32: error: cannot evaluate type expression [TypeExprEvaluationFailure]
+// CHECK:STDERR: fail_todo_float.carbon:[[@LINE+4]]:32: error: cannot evaluate type expression [TypeExprEvaluationFailure]
 // CHECK:STDERR: fn F[N:! Core.IntLiteral()](n: Core.Float(N)) -> Core.IntLiteral() {
 // CHECK:STDERR:                                ^~~~~~~~~~~~~
+// CHECK:STDERR:
 fn F[N:! Core.IntLiteral()](n: Core.Float(N)) -> Core.IntLiteral() {
   return N;
 }
@@ -207,35 +208,35 @@ fn G(a: f64) -> Core.IntLiteral() {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %Core.import = import Core
 // CHECK:STDOUT:   %F.decl: %F.type = fn_decl @F [template = constants.%F] {
-// CHECK:STDOUT:     %N.patt.loc8_6.1: Core.IntLiteral = symbolic_binding_pattern N, 0 [symbolic = %N.patt.loc8_6.2 (constants.%N.patt)]
-// CHECK:STDOUT:     %N.param_patt: Core.IntLiteral = value_param_pattern %N.patt.loc8_6.1, runtime_param<invalid> [symbolic = %N.patt.loc8_6.2 (constants.%N.patt)]
+// CHECK:STDOUT:     %N.patt.loc9_6.1: Core.IntLiteral = symbolic_binding_pattern N, 0 [symbolic = %N.patt.loc9_6.2 (constants.%N.patt)]
+// CHECK:STDOUT:     %N.param_patt: Core.IntLiteral = value_param_pattern %N.patt.loc9_6.1, runtime_param<invalid> [symbolic = %N.patt.loc9_6.2 (constants.%N.patt)]
 // CHECK:STDOUT:     %n.patt: <error> = binding_pattern n
 // CHECK:STDOUT:     %n.param_patt: <error> = value_param_pattern %n.patt, runtime_param0
 // CHECK:STDOUT:     %return.patt: Core.IntLiteral = return_slot_pattern
 // CHECK:STDOUT:     %return.param_patt: Core.IntLiteral = out_param_pattern %return.patt, runtime_param1
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %Core.ref.loc8_50: <namespace> = name_ref Core, imports.%Core [template = imports.%Core]
-// CHECK:STDOUT:     %IntLiteral.ref.loc8_54: %IntLiteral.type = name_ref IntLiteral, imports.%import_ref.72f [template = constants.%IntLiteral]
-// CHECK:STDOUT:     %int_literal.make_type.loc8_66: init type = call %IntLiteral.ref.loc8_54() [template = Core.IntLiteral]
-// CHECK:STDOUT:     %.loc8_66.1: type = value_of_initializer %int_literal.make_type.loc8_66 [template = Core.IntLiteral]
-// CHECK:STDOUT:     %.loc8_66.2: type = converted %int_literal.make_type.loc8_66, %.loc8_66.1 [template = Core.IntLiteral]
+// CHECK:STDOUT:     %Core.ref.loc9_50: <namespace> = name_ref Core, imports.%Core [template = imports.%Core]
+// CHECK:STDOUT:     %IntLiteral.ref.loc9_54: %IntLiteral.type = name_ref IntLiteral, imports.%import_ref.72f [template = constants.%IntLiteral]
+// CHECK:STDOUT:     %int_literal.make_type.loc9_66: init type = call %IntLiteral.ref.loc9_54() [template = Core.IntLiteral]
+// CHECK:STDOUT:     %.loc9_66.1: type = value_of_initializer %int_literal.make_type.loc9_66 [template = Core.IntLiteral]
+// CHECK:STDOUT:     %.loc9_66.2: type = converted %int_literal.make_type.loc9_66, %.loc9_66.1 [template = Core.IntLiteral]
 // CHECK:STDOUT:     %N.param: Core.IntLiteral = value_param runtime_param<invalid>
-// CHECK:STDOUT:     %.loc8_26.1: type = splice_block %.loc8_26.3 [template = Core.IntLiteral] {
-// CHECK:STDOUT:       %Core.ref.loc8_10: <namespace> = name_ref Core, imports.%Core [template = imports.%Core]
-// CHECK:STDOUT:       %IntLiteral.ref.loc8_14: %IntLiteral.type = name_ref IntLiteral, imports.%import_ref.72f [template = constants.%IntLiteral]
-// CHECK:STDOUT:       %int_literal.make_type.loc8_26: init type = call %IntLiteral.ref.loc8_14() [template = Core.IntLiteral]
-// CHECK:STDOUT:       %.loc8_26.2: type = value_of_initializer %int_literal.make_type.loc8_26 [template = Core.IntLiteral]
-// CHECK:STDOUT:       %.loc8_26.3: type = converted %int_literal.make_type.loc8_26, %.loc8_26.2 [template = Core.IntLiteral]
+// CHECK:STDOUT:     %.loc9_26.1: type = splice_block %.loc9_26.3 [template = Core.IntLiteral] {
+// CHECK:STDOUT:       %Core.ref.loc9_10: <namespace> = name_ref Core, imports.%Core [template = imports.%Core]
+// CHECK:STDOUT:       %IntLiteral.ref.loc9_14: %IntLiteral.type = name_ref IntLiteral, imports.%import_ref.72f [template = constants.%IntLiteral]
+// CHECK:STDOUT:       %int_literal.make_type.loc9_26: init type = call %IntLiteral.ref.loc9_14() [template = Core.IntLiteral]
+// CHECK:STDOUT:       %.loc9_26.2: type = value_of_initializer %int_literal.make_type.loc9_26 [template = Core.IntLiteral]
+// CHECK:STDOUT:       %.loc9_26.3: type = converted %int_literal.make_type.loc9_26, %.loc9_26.2 [template = Core.IntLiteral]
 // CHECK:STDOUT:     }
-// CHECK:STDOUT:     %N.loc8_6.1: Core.IntLiteral = bind_symbolic_name N, 0, %N.param [symbolic = %N.loc8_6.2 (constants.%N)]
+// CHECK:STDOUT:     %N.loc9_6.1: Core.IntLiteral = bind_symbolic_name N, 0, %N.param [symbolic = %N.loc9_6.2 (constants.%N)]
 // CHECK:STDOUT:     %n.param: <error> = value_param runtime_param0
 // CHECK:STDOUT:     %.1: <error> = splice_block <error> [template = <error>] {
-// CHECK:STDOUT:       %Core.ref.loc8_32: <namespace> = name_ref Core, imports.%Core [template = imports.%Core]
+// CHECK:STDOUT:       %Core.ref.loc9_32: <namespace> = name_ref Core, imports.%Core [template = imports.%Core]
 // CHECK:STDOUT:       %Float.ref: %Float.type = name_ref Float, imports.%import_ref.1d6 [template = constants.%Float]
-// CHECK:STDOUT:       %N.ref.loc8: Core.IntLiteral = name_ref N, %N.loc8_6.1 [symbolic = %N.loc8_6.2 (constants.%N)]
-// CHECK:STDOUT:       %float.make_type: init type = call %Float.ref(%N.ref.loc8)
-// CHECK:STDOUT:       %.loc8_44.1: type = value_of_initializer %float.make_type
-// CHECK:STDOUT:       %.loc8_44.2: type = converted %float.make_type, %.loc8_44.1
+// CHECK:STDOUT:       %N.ref.loc9: Core.IntLiteral = name_ref N, %N.loc9_6.1 [symbolic = %N.loc9_6.2 (constants.%N)]
+// CHECK:STDOUT:       %float.make_type: init type = call %Float.ref(%N.ref.loc9)
+// CHECK:STDOUT:       %.loc9_44.1: type = value_of_initializer %float.make_type
+// CHECK:STDOUT:       %.loc9_44.2: type = converted %float.make_type, %.loc9_44.1
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %n: <error> = bind_name n, %n.param
 // CHECK:STDOUT:     %return.param: ref Core.IntLiteral = out_param runtime_param1
@@ -250,14 +251,14 @@ fn G(a: f64) -> Core.IntLiteral() {
 // CHECK:STDOUT:     %Core.ref: <namespace> = name_ref Core, imports.%Core [template = imports.%Core]
 // CHECK:STDOUT:     %IntLiteral.ref: %IntLiteral.type = name_ref IntLiteral, imports.%import_ref.72f [template = constants.%IntLiteral]
 // CHECK:STDOUT:     %int_literal.make_type: init type = call %IntLiteral.ref() [template = Core.IntLiteral]
-// CHECK:STDOUT:     %.loc12_33.1: type = value_of_initializer %int_literal.make_type [template = Core.IntLiteral]
-// CHECK:STDOUT:     %.loc12_33.2: type = converted %int_literal.make_type, %.loc12_33.1 [template = Core.IntLiteral]
+// CHECK:STDOUT:     %.loc13_33.1: type = value_of_initializer %int_literal.make_type [template = Core.IntLiteral]
+// CHECK:STDOUT:     %.loc13_33.2: type = converted %int_literal.make_type, %.loc13_33.1 [template = Core.IntLiteral]
 // CHECK:STDOUT:     %a.param: f64 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc12_9.1: type = splice_block %.loc12_9.3 [template = f64] {
+// CHECK:STDOUT:     %.loc13_9.1: type = splice_block %.loc13_9.3 [template = f64] {
 // CHECK:STDOUT:       %int_64: Core.IntLiteral = int_value 64 [template = constants.%int_64]
 // CHECK:STDOUT:       %float.make_type: init type = call constants.%Float(%int_64) [template = f64]
-// CHECK:STDOUT:       %.loc12_9.2: type = value_of_initializer %float.make_type [template = f64]
-// CHECK:STDOUT:       %.loc12_9.3: type = converted %float.make_type, %.loc12_9.2 [template = f64]
+// CHECK:STDOUT:       %.loc13_9.2: type = value_of_initializer %float.make_type [template = f64]
+// CHECK:STDOUT:       %.loc13_9.3: type = converted %float.make_type, %.loc13_9.2 [template = f64]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: f64 = bind_name a, %a.param
 // CHECK:STDOUT:     %return.param: ref Core.IntLiteral = out_param runtime_param1
@@ -265,16 +266,16 @@ fn G(a: f64) -> Core.IntLiteral() {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: generic fn @F(%N.loc8_6.1: Core.IntLiteral) {
-// CHECK:STDOUT:   %N.loc8_6.2: Core.IntLiteral = bind_symbolic_name N, 0 [symbolic = %N.loc8_6.2 (constants.%N)]
-// CHECK:STDOUT:   %N.patt.loc8_6.2: Core.IntLiteral = symbolic_binding_pattern N, 0 [symbolic = %N.patt.loc8_6.2 (constants.%N.patt)]
+// CHECK:STDOUT: generic fn @F(%N.loc9_6.1: Core.IntLiteral) {
+// CHECK:STDOUT:   %N.loc9_6.2: Core.IntLiteral = bind_symbolic_name N, 0 [symbolic = %N.loc9_6.2 (constants.%N)]
+// CHECK:STDOUT:   %N.patt.loc9_6.2: Core.IntLiteral = symbolic_binding_pattern N, 0 [symbolic = %N.patt.loc9_6.2 (constants.%N.patt)]
 // CHECK:STDOUT:
 // CHECK:STDOUT: !definition:
 // CHECK:STDOUT:
 // CHECK:STDOUT:   fn[%N.param_patt: Core.IntLiteral](%n.param_patt: <error>) -> Core.IntLiteral {
 // CHECK:STDOUT:   !entry:
-// CHECK:STDOUT:     %N.ref.loc9: Core.IntLiteral = name_ref N, %N.loc8_6.1 [symbolic = %N.loc8_6.2 (constants.%N)]
-// CHECK:STDOUT:     return %N.ref.loc9
+// CHECK:STDOUT:     %N.ref.loc10: Core.IntLiteral = name_ref N, %N.loc9_6.1 [symbolic = %N.loc9_6.2 (constants.%N)]
+// CHECK:STDOUT:     return %N.ref.loc10
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -286,7 +287,7 @@ fn G(a: f64) -> Core.IntLiteral() {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @F(constants.%N) {
-// CHECK:STDOUT:   %N.loc8_6.2 => constants.%N
-// CHECK:STDOUT:   %N.patt.loc8_6.2 => constants.%N
+// CHECK:STDOUT:   %N.loc9_6.2 => constants.%N
+// CHECK:STDOUT:   %N.patt.loc9_6.2 => constants.%N
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/deduce/tuple.carbon b/toolchain/check/testdata/deduce/tuple.carbon
index 141b01498b12..650c883d7d0d 100644
--- a/toolchain/check/testdata/deduce/tuple.carbon
+++ b/toolchain/check/testdata/deduce/tuple.carbon
@@ -43,12 +43,13 @@ class D {}
 fn F[T:! type](pair: (T, T)) -> T;
 
 fn G(pair: (C, D)) -> D {
-  // CHECK:STDERR: fail_inconsistent.carbon:[[@LINE+6]]:10: error: inconsistent deductions for value of generic parameter `T` [DeductionInconsistent]
+  // CHECK:STDERR: fail_inconsistent.carbon:[[@LINE+7]]:10: error: inconsistent deductions for value of generic parameter `T` [DeductionInconsistent]
   // CHECK:STDERR:   return F(pair);
   // CHECK:STDERR:          ^~~~~~~
   // CHECK:STDERR: fail_inconsistent.carbon:[[@LINE-6]]:1: note: while deducing parameters of generic declared here [DeductionGenericHere]
   // CHECK:STDERR: fn F[T:! type](pair: (T, T)) -> T;
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   return F(pair);
 }
 
diff --git a/toolchain/check/testdata/deduce/type_operator.carbon b/toolchain/check/testdata/deduce/type_operator.carbon
index daf849623f8b..eae445e3a04d 100644
--- a/toolchain/check/testdata/deduce/type_operator.carbon
+++ b/toolchain/check/testdata/deduce/type_operator.carbon
@@ -53,12 +53,13 @@ class C {}
 fn F[T:! type](p: const T*) -> T { return F(p); }
 
 fn G(p: C*) -> const C {
-  // CHECK:STDERR: fail_const_from_nonconst.carbon:[[@LINE+6]]:10: error: cannot deduce value for generic parameter `T` [DeductionIncomplete]
+  // CHECK:STDERR: fail_const_from_nonconst.carbon:[[@LINE+7]]:10: error: cannot deduce value for generic parameter `T` [DeductionIncomplete]
   // CHECK:STDERR:   return F(p);
   // CHECK:STDERR:          ^~~~
   // CHECK:STDERR: fail_const_from_nonconst.carbon:[[@LINE-6]]:1: note: while deducing parameters of generic declared here [DeductionGenericHere]
   // CHECK:STDERR: fn F[T:! type](p: const T*) -> T { return F(p); }
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   return F(p);
 }
 
diff --git a/toolchain/check/testdata/eval/fail_aggregate.carbon b/toolchain/check/testdata/eval/fail_aggregate.carbon
index 34c7881d2927..00b0158ac442 100644
--- a/toolchain/check/testdata/eval/fail_aggregate.carbon
+++ b/toolchain/check/testdata/eval/fail_aggregate.carbon
@@ -10,9 +10,10 @@
 
 // TODO: This creates an array temporary, which we don't yet support evaluating.
 
-// CHECK:STDERR: fail_aggregate.carbon:[[@LINE+3]]:43: error: array bound is not a constant [InvalidArrayExpr]
+// CHECK:STDERR: fail_aggregate.carbon:[[@LINE+4]]:43: error: array bound is not a constant [InvalidArrayExpr]
 // CHECK:STDERR: var array_index: [i32; 1] = (0,) as [i32; ((5, 7, 1, 9) as [i32; 4])[2]];
 // CHECK:STDERR:                                           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 var array_index: [i32; 1] = (0,) as [i32; ((5, 7, 1, 9) as [i32; 4])[2]];
 
 // CHECK:STDOUT: --- fail_aggregate.carbon
@@ -75,66 +76,66 @@ var array_index: [i32; 1] = (0,) as [i32; ((5, 7, 1, 9) as [i32; 4])[2]];
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %int_0.loc16_30: Core.IntLiteral = int_value 0 [template = constants.%int_0]
-// CHECK:STDOUT:   %.loc16_32: %tuple.type.985 = tuple_literal (%int_0.loc16_30)
-// CHECK:STDOUT:   %int_32.loc16_38: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:   %i32.loc16_38: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:   %int_0.loc17_30: Core.IntLiteral = int_value 0 [template = constants.%int_0]
+// CHECK:STDOUT:   %.loc17_32: %tuple.type.985 = tuple_literal (%int_0.loc17_30)
+// CHECK:STDOUT:   %int_32.loc17_38: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:   %i32.loc17_38: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
 // CHECK:STDOUT:   %int_5: Core.IntLiteral = int_value 5 [template = constants.%int_5.64b]
 // CHECK:STDOUT:   %int_7: Core.IntLiteral = int_value 7 [template = constants.%int_7.29f]
-// CHECK:STDOUT:   %int_1.loc16_51: Core.IntLiteral = int_value 1 [template = constants.%int_1.5b8]
+// CHECK:STDOUT:   %int_1.loc17_51: Core.IntLiteral = int_value 1 [template = constants.%int_1.5b8]
 // CHECK:STDOUT:   %int_9: Core.IntLiteral = int_value 9 [template = constants.%int_9.988]
-// CHECK:STDOUT:   %.loc16_55.1: %tuple.type.d46 = tuple_literal (%int_5, %int_7, %int_1.loc16_51, %int_9)
-// CHECK:STDOUT:   %int_32.loc16_61: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:   %i32.loc16_61: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:   %.loc17_55.1: %tuple.type.d46 = tuple_literal (%int_5, %int_7, %int_1.loc17_51, %int_9)
+// CHECK:STDOUT:   %int_32.loc17_61: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:   %i32.loc17_61: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
 // CHECK:STDOUT:   %int_4: Core.IntLiteral = int_value 4 [template = constants.%int_4]
 // CHECK:STDOUT:   %array_type: type = array_type %int_4, %i32 [template = constants.%array_type.f32]
-// CHECK:STDOUT:   %impl.elem0.loc16_55.1: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
-// CHECK:STDOUT:   %Convert.bound.loc16_55.1: <bound method> = bound_method %int_5, %impl.elem0.loc16_55.1 [template = constants.%Convert.bound.4e6]
-// CHECK:STDOUT:   %Convert.specific_fn.loc16_55.1: <specific function> = specific_function %Convert.bound.loc16_55.1, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.ba9]
-// CHECK:STDOUT:   %int.convert_checked.loc16_55.1: init %i32 = call %Convert.specific_fn.loc16_55.1(%int_5) [template = constants.%int_5.0f6]
-// CHECK:STDOUT:   %.loc16_55.2: init %i32 = converted %int_5, %int.convert_checked.loc16_55.1 [template = constants.%int_5.0f6]
-// CHECK:STDOUT:   %.loc16_55.3: ref %array_type.f32 = temporary_storage
-// CHECK:STDOUT:   %int_0.loc16_55: Core.IntLiteral = int_value 0 [template = constants.%int_0]
-// CHECK:STDOUT:   %.loc16_55.4: ref %i32 = array_index %.loc16_55.3, %int_0.loc16_55
-// CHECK:STDOUT:   %.loc16_55.5: init %i32 = initialize_from %.loc16_55.2 to %.loc16_55.4 [template = constants.%int_5.0f6]
-// CHECK:STDOUT:   %impl.elem0.loc16_55.2: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
-// CHECK:STDOUT:   %Convert.bound.loc16_55.2: <bound method> = bound_method %int_7, %impl.elem0.loc16_55.2 [template = constants.%Convert.bound.208]
-// CHECK:STDOUT:   %Convert.specific_fn.loc16_55.2: <specific function> = specific_function %Convert.bound.loc16_55.2, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.c12]
-// CHECK:STDOUT:   %int.convert_checked.loc16_55.2: init %i32 = call %Convert.specific_fn.loc16_55.2(%int_7) [template = constants.%int_7.0b1]
-// CHECK:STDOUT:   %.loc16_55.6: init %i32 = converted %int_7, %int.convert_checked.loc16_55.2 [template = constants.%int_7.0b1]
-// CHECK:STDOUT:   %int_1.loc16_55: Core.IntLiteral = int_value 1 [template = constants.%int_1.5b8]
-// CHECK:STDOUT:   %.loc16_55.7: ref %i32 = array_index %.loc16_55.3, %int_1.loc16_55
-// CHECK:STDOUT:   %.loc16_55.8: init %i32 = initialize_from %.loc16_55.6 to %.loc16_55.7 [template = constants.%int_7.0b1]
-// CHECK:STDOUT:   %impl.elem0.loc16_55.3: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
-// CHECK:STDOUT:   %Convert.bound.loc16_55.3: <bound method> = bound_method %int_1.loc16_51, %impl.elem0.loc16_55.3 [template = constants.%Convert.bound.ab5]
-// CHECK:STDOUT:   %Convert.specific_fn.loc16_55.3: <specific function> = specific_function %Convert.bound.loc16_55.3, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.70c]
-// CHECK:STDOUT:   %int.convert_checked.loc16_55.3: init %i32 = call %Convert.specific_fn.loc16_55.3(%int_1.loc16_51) [template = constants.%int_1.5d2]
-// CHECK:STDOUT:   %.loc16_55.9: init %i32 = converted %int_1.loc16_51, %int.convert_checked.loc16_55.3 [template = constants.%int_1.5d2]
-// CHECK:STDOUT:   %int_2.loc16_55: Core.IntLiteral = int_value 2 [template = constants.%int_2.ecc]
-// CHECK:STDOUT:   %.loc16_55.10: ref %i32 = array_index %.loc16_55.3, %int_2.loc16_55
-// CHECK:STDOUT:   %.loc16_55.11: init %i32 = initialize_from %.loc16_55.9 to %.loc16_55.10 [template = constants.%int_1.5d2]
-// CHECK:STDOUT:   %impl.elem0.loc16_55.4: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
-// CHECK:STDOUT:   %Convert.bound.loc16_55.4: <bound method> = bound_method %int_9, %impl.elem0.loc16_55.4 [template = constants.%Convert.bound.9e2]
-// CHECK:STDOUT:   %Convert.specific_fn.loc16_55.4: <specific function> = specific_function %Convert.bound.loc16_55.4, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.b02]
-// CHECK:STDOUT:   %int.convert_checked.loc16_55.4: init %i32 = call %Convert.specific_fn.loc16_55.4(%int_9) [template = constants.%int_9.f88]
-// CHECK:STDOUT:   %.loc16_55.12: init %i32 = converted %int_9, %int.convert_checked.loc16_55.4 [template = constants.%int_9.f88]
+// CHECK:STDOUT:   %impl.elem0.loc17_55.1: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
+// CHECK:STDOUT:   %Convert.bound.loc17_55.1: <bound method> = bound_method %int_5, %impl.elem0.loc17_55.1 [template = constants.%Convert.bound.4e6]
+// CHECK:STDOUT:   %Convert.specific_fn.loc17_55.1: <specific function> = specific_function %Convert.bound.loc17_55.1, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.ba9]
+// CHECK:STDOUT:   %int.convert_checked.loc17_55.1: init %i32 = call %Convert.specific_fn.loc17_55.1(%int_5) [template = constants.%int_5.0f6]
+// CHECK:STDOUT:   %.loc17_55.2: init %i32 = converted %int_5, %int.convert_checked.loc17_55.1 [template = constants.%int_5.0f6]
+// CHECK:STDOUT:   %.loc17_55.3: ref %array_type.f32 = temporary_storage
+// CHECK:STDOUT:   %int_0.loc17_55: Core.IntLiteral = int_value 0 [template = constants.%int_0]
+// CHECK:STDOUT:   %.loc17_55.4: ref %i32 = array_index %.loc17_55.3, %int_0.loc17_55
+// CHECK:STDOUT:   %.loc17_55.5: init %i32 = initialize_from %.loc17_55.2 to %.loc17_55.4 [template = constants.%int_5.0f6]
+// CHECK:STDOUT:   %impl.elem0.loc17_55.2: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
+// CHECK:STDOUT:   %Convert.bound.loc17_55.2: <bound method> = bound_method %int_7, %impl.elem0.loc17_55.2 [template = constants.%Convert.bound.208]
+// CHECK:STDOUT:   %Convert.specific_fn.loc17_55.2: <specific function> = specific_function %Convert.bound.loc17_55.2, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.c12]
+// CHECK:STDOUT:   %int.convert_checked.loc17_55.2: init %i32 = call %Convert.specific_fn.loc17_55.2(%int_7) [template = constants.%int_7.0b1]
+// CHECK:STDOUT:   %.loc17_55.6: init %i32 = converted %int_7, %int.convert_checked.loc17_55.2 [template = constants.%int_7.0b1]
+// CHECK:STDOUT:   %int_1.loc17_55: Core.IntLiteral = int_value 1 [template = constants.%int_1.5b8]
+// CHECK:STDOUT:   %.loc17_55.7: ref %i32 = array_index %.loc17_55.3, %int_1.loc17_55
+// CHECK:STDOUT:   %.loc17_55.8: init %i32 = initialize_from %.loc17_55.6 to %.loc17_55.7 [template = constants.%int_7.0b1]
+// CHECK:STDOUT:   %impl.elem0.loc17_55.3: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
+// CHECK:STDOUT:   %Convert.bound.loc17_55.3: <bound method> = bound_method %int_1.loc17_51, %impl.elem0.loc17_55.3 [template = constants.%Convert.bound.ab5]
+// CHECK:STDOUT:   %Convert.specific_fn.loc17_55.3: <specific function> = specific_function %Convert.bound.loc17_55.3, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.70c]
+// CHECK:STDOUT:   %int.convert_checked.loc17_55.3: init %i32 = call %Convert.specific_fn.loc17_55.3(%int_1.loc17_51) [template = constants.%int_1.5d2]
+// CHECK:STDOUT:   %.loc17_55.9: init %i32 = converted %int_1.loc17_51, %int.convert_checked.loc17_55.3 [template = constants.%int_1.5d2]
+// CHECK:STDOUT:   %int_2.loc17_55: Core.IntLiteral = int_value 2 [template = constants.%int_2.ecc]
+// CHECK:STDOUT:   %.loc17_55.10: ref %i32 = array_index %.loc17_55.3, %int_2.loc17_55
+// CHECK:STDOUT:   %.loc17_55.11: init %i32 = initialize_from %.loc17_55.9 to %.loc17_55.10 [template = constants.%int_1.5d2]
+// CHECK:STDOUT:   %impl.elem0.loc17_55.4: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
+// CHECK:STDOUT:   %Convert.bound.loc17_55.4: <bound method> = bound_method %int_9, %impl.elem0.loc17_55.4 [template = constants.%Convert.bound.9e2]
+// CHECK:STDOUT:   %Convert.specific_fn.loc17_55.4: <specific function> = specific_function %Convert.bound.loc17_55.4, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.b02]
+// CHECK:STDOUT:   %int.convert_checked.loc17_55.4: init %i32 = call %Convert.specific_fn.loc17_55.4(%int_9) [template = constants.%int_9.f88]
+// CHECK:STDOUT:   %.loc17_55.12: init %i32 = converted %int_9, %int.convert_checked.loc17_55.4 [template = constants.%int_9.f88]
 // CHECK:STDOUT:   %int_3: Core.IntLiteral = int_value 3 [template = constants.%int_3]
-// CHECK:STDOUT:   %.loc16_55.13: ref %i32 = array_index %.loc16_55.3, %int_3
-// CHECK:STDOUT:   %.loc16_55.14: init %i32 = initialize_from %.loc16_55.12 to %.loc16_55.13 [template = constants.%int_9.f88]
-// CHECK:STDOUT:   %.loc16_55.15: init %array_type.f32 = array_init (%.loc16_55.5, %.loc16_55.8, %.loc16_55.11, %.loc16_55.14) to %.loc16_55.3 [template = constants.%array]
-// CHECK:STDOUT:   %.loc16_57.1: init %array_type.f32 = converted %.loc16_55.1, %.loc16_55.15 [template = constants.%array]
-// CHECK:STDOUT:   %int_2.loc16_70: Core.IntLiteral = int_value 2 [template = constants.%int_2.ecc]
-// CHECK:STDOUT:   %.loc16_57.2: ref %array_type.f32 = temporary %.loc16_55.3, %.loc16_57.1
-// CHECK:STDOUT:   %int_32.loc16_71: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:   %i32.loc16_71: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
-// CHECK:STDOUT:   %impl.elem0.loc16_70: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
-// CHECK:STDOUT:   %Convert.bound.loc16_70: <bound method> = bound_method %int_2.loc16_70, %impl.elem0.loc16_70 [template = constants.%Convert.bound.ef9]
-// CHECK:STDOUT:   %Convert.specific_fn.loc16_70: <specific function> = specific_function %Convert.bound.loc16_70, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.787]
-// CHECK:STDOUT:   %int.convert_checked.loc16_70: init %i32 = call %Convert.specific_fn.loc16_70(%int_2.loc16_70) [template = constants.%int_2.ef8]
-// CHECK:STDOUT:   %.loc16_70.1: %i32 = value_of_initializer %int.convert_checked.loc16_70 [template = constants.%int_2.ef8]
-// CHECK:STDOUT:   %.loc16_70.2: %i32 = converted %int_2.loc16_70, %.loc16_70.1 [template = constants.%int_2.ef8]
-// CHECK:STDOUT:   %.loc16_71.1: ref %i32 = array_index %.loc16_57.2, %.loc16_70.2
-// CHECK:STDOUT:   %.loc16_71.2: %i32 = bind_value %.loc16_71.1
+// CHECK:STDOUT:   %.loc17_55.13: ref %i32 = array_index %.loc17_55.3, %int_3
+// CHECK:STDOUT:   %.loc17_55.14: init %i32 = initialize_from %.loc17_55.12 to %.loc17_55.13 [template = constants.%int_9.f88]
+// CHECK:STDOUT:   %.loc17_55.15: init %array_type.f32 = array_init (%.loc17_55.5, %.loc17_55.8, %.loc17_55.11, %.loc17_55.14) to %.loc17_55.3 [template = constants.%array]
+// CHECK:STDOUT:   %.loc17_57.1: init %array_type.f32 = converted %.loc17_55.1, %.loc17_55.15 [template = constants.%array]
+// CHECK:STDOUT:   %int_2.loc17_70: Core.IntLiteral = int_value 2 [template = constants.%int_2.ecc]
+// CHECK:STDOUT:   %.loc17_57.2: ref %array_type.f32 = temporary %.loc17_55.3, %.loc17_57.1
+// CHECK:STDOUT:   %int_32.loc17_71: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:   %i32.loc17_71: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:   %impl.elem0.loc17_70: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
+// CHECK:STDOUT:   %Convert.bound.loc17_70: <bound method> = bound_method %int_2.loc17_70, %impl.elem0.loc17_70 [template = constants.%Convert.bound.ef9]
+// CHECK:STDOUT:   %Convert.specific_fn.loc17_70: <specific function> = specific_function %Convert.bound.loc17_70, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.787]
+// CHECK:STDOUT:   %int.convert_checked.loc17_70: init %i32 = call %Convert.specific_fn.loc17_70(%int_2.loc17_70) [template = constants.%int_2.ef8]
+// CHECK:STDOUT:   %.loc17_70.1: %i32 = value_of_initializer %int.convert_checked.loc17_70 [template = constants.%int_2.ef8]
+// CHECK:STDOUT:   %.loc17_70.2: %i32 = converted %int_2.loc17_70, %.loc17_70.1 [template = constants.%int_2.ef8]
+// CHECK:STDOUT:   %.loc17_71.1: ref %i32 = array_index %.loc17_57.2, %.loc17_70.2
+// CHECK:STDOUT:   %.loc17_71.2: %i32 = bind_value %.loc17_71.1
 // CHECK:STDOUT:   assign file.%array_index.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/function/builtin/fail_redefined.carbon b/toolchain/check/testdata/function/builtin/fail_redefined.carbon
index e53e0362dbae..516b14301500 100644
--- a/toolchain/check/testdata/function/builtin/fail_redefined.carbon
+++ b/toolchain/check/testdata/function/builtin/fail_redefined.carbon
@@ -29,12 +29,13 @@ fn B(n: i32, m: i32) -> i32 { return n; }
 fn B(n: i32, m: i32) -> i32 = "int.sadd";
 
 fn C(n: i32, m: i32) -> i32 = "int.sadd";
-// CHECK:STDERR: fail_redefined.carbon:[[@LINE+6]]:1: error: redefinition of `fn C` [RedeclRedef]
+// CHECK:STDERR: fail_redefined.carbon:[[@LINE+7]]:1: error: redefinition of `fn C` [RedeclRedef]
 // CHECK:STDERR: fn C(n: i32, m: i32) -> i32 = "int.sadd";
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_redefined.carbon:[[@LINE-4]]:1: note: previously defined here [RedeclPrevDef]
 // CHECK:STDERR: fn C(n: i32, m: i32) -> i32 = "int.sadd";
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 fn C(n: i32, m: i32) -> i32 = "int.sadd";
 
 // CHECK:STDOUT: --- fail_redefined.carbon
@@ -197,7 +198,7 @@ fn C(n: i32, m: i32) -> i32 = "int.sadd";
 // CHECK:STDOUT:     %return.param: ref %i32 = out_param runtime_param2
 // CHECK:STDOUT:     %return: ref %i32 = return_slot %return.param
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %.decl.loc38: %.type.b6a92a.3 = fn_decl @.3 [template = constants.%.d852be.3] {
+// CHECK:STDOUT:   %.decl.loc39: %.type.b6a92a.3 = fn_decl @.3 [template = constants.%.d852be.3] {
 // CHECK:STDOUT:     %n.patt: %i32 = binding_pattern n
 // CHECK:STDOUT:     %n.param_patt: %i32 = value_param_pattern %n.patt, runtime_param0
 // CHECK:STDOUT:     %m.patt: %i32 = binding_pattern m
@@ -205,18 +206,18 @@ fn C(n: i32, m: i32) -> i32 = "int.sadd";
 // CHECK:STDOUT:     %return.patt: %i32 = return_slot_pattern
 // CHECK:STDOUT:     %return.param_patt: %i32 = out_param_pattern %return.patt, runtime_param2
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %int_32.loc38_25: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:     %i32.loc38_25: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:     %int_32.loc39_25: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:     %i32.loc39_25: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
 // CHECK:STDOUT:     %n.param: %i32 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc38_9: type = splice_block %i32.loc38_9 [template = constants.%i32] {
-// CHECK:STDOUT:       %int_32.loc38_9: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:       %i32.loc38_9: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:     %.loc39_9: type = splice_block %i32.loc39_9 [template = constants.%i32] {
+// CHECK:STDOUT:       %int_32.loc39_9: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:       %i32.loc39_9: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %n: %i32 = bind_name n, %n.param
 // CHECK:STDOUT:     %m.param: %i32 = value_param runtime_param1
-// CHECK:STDOUT:     %.loc38_17: type = splice_block %i32.loc38_17 [template = constants.%i32] {
-// CHECK:STDOUT:       %int_32.loc38_17: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:       %i32.loc38_17: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:     %.loc39_17: type = splice_block %i32.loc39_17 [template = constants.%i32] {
+// CHECK:STDOUT:       %int_32.loc39_17: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:       %i32.loc39_17: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %m: %i32 = bind_name m, %m.param
 // CHECK:STDOUT:     %return.param: ref %i32 = out_param runtime_param2
diff --git a/toolchain/check/testdata/function/builtin/fail_unknown.carbon b/toolchain/check/testdata/function/builtin/fail_unknown.carbon
index 8d26be2113ac..8fca7b19baf7 100644
--- a/toolchain/check/testdata/function/builtin/fail_unknown.carbon
+++ b/toolchain/check/testdata/function/builtin/fail_unknown.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/builtin/fail_unknown.carbon
 
-// CHECK:STDERR: fail_unknown.carbon:[[@LINE+3]]:23: error: unknown builtin function name "unknown.builtin.name" [UnknownBuiltinFunctionName]
+// CHECK:STDERR: fail_unknown.carbon:[[@LINE+4]]:23: error: unknown builtin function name "unknown.builtin.name" [UnknownBuiltinFunctionName]
 // CHECK:STDERR: fn UnknownBuiltin() = "unknown.builtin.name";
 // CHECK:STDERR:                       ^~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 fn UnknownBuiltin() = "unknown.builtin.name";
 
 // CHECK:STDOUT: --- fail_unknown.carbon
diff --git a/toolchain/check/testdata/function/builtin/no_prelude/adapted_type.carbon b/toolchain/check/testdata/function/builtin/no_prelude/adapted_type.carbon
index ddc67eb19309..0dbc955f4d2d 100644
--- a/toolchain/check/testdata/function/builtin/no_prelude/adapted_type.carbon
+++ b/toolchain/check/testdata/function/builtin/no_prelude/adapted_type.carbon
@@ -40,9 +40,10 @@ class MyIntLiteral {
   adapt {};
 }
 
-// CHECK:STDERR: fail_bad_adapt.carbon:[[@LINE+3]]:1: error: invalid signature for builtin function "int.make_type_signed" [InvalidBuiltinSignature]
+// CHECK:STDERR: fail_bad_adapt.carbon:[[@LINE+4]]:1: error: invalid signature for builtin function "int.make_type_signed" [InvalidBuiltinSignature]
 // CHECK:STDERR: fn Int(N: MyIntLiteral) -> type = "int.make_type_signed";
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 fn Int(N: MyIntLiteral) -> type = "int.make_type_signed";
 
 // CHECK:STDOUT: --- adapt.carbon
diff --git a/toolchain/check/testdata/function/call/fail_not_callable.carbon b/toolchain/check/testdata/function/call/fail_not_callable.carbon
index df79412f46cb..48cf89e29cca 100644
--- a/toolchain/check/testdata/function/call/fail_not_callable.carbon
+++ b/toolchain/check/testdata/function/call/fail_not_callable.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/call/fail_not_callable.carbon
 
 fn Run() {
-  // CHECK:STDERR: fail_not_callable.carbon:[[@LINE+3]]:16: error: value of type `String` is not callable [CallToNonCallable]
+  // CHECK:STDERR: fail_not_callable.carbon:[[@LINE+4]]:16: error: value of type `String` is not callable [CallToNonCallable]
   // CHECK:STDERR:   var x: i32 = "hello"();
   // CHECK:STDERR:                ^~~~~~~~~
+  // CHECK:STDERR:
   var x: i32 = "hello"();
 }
 
diff --git a/toolchain/check/testdata/function/call/fail_param_count.carbon b/toolchain/check/testdata/function/call/fail_param_count.carbon
index ed88ec5c01f1..24f096da6fcb 100644
--- a/toolchain/check/testdata/function/call/fail_param_count.carbon
+++ b/toolchain/check/testdata/function/call/fail_param_count.carbon
@@ -55,12 +55,13 @@ fn Main() {
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~
   // CHECK:STDERR:
   Run2();
-  // CHECK:STDERR: fail_param_count.carbon:[[@LINE+6]]:3: error: 1 argument passed to function expecting 2 arguments [CallArgCountMismatch]
+  // CHECK:STDERR: fail_param_count.carbon:[[@LINE+7]]:3: error: 1 argument passed to function expecting 2 arguments [CallArgCountMismatch]
   // CHECK:STDERR:   Run2(0);
   // CHECK:STDERR:   ^~~~~~~
   // CHECK:STDERR: fail_param_count.carbon:[[@LINE-48]]:1: note: calling function declared here [InCallToEntity]
   // CHECK:STDERR: fn Run2(a: i32, b: i32) {}
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   Run2(0);
 }
 
@@ -159,8 +160,8 @@ fn Main() {
 // CHECK:STDOUT:   %int_0.loc48: Core.IntLiteral = int_value 0 [template = constants.%int_0]
 // CHECK:STDOUT:   %int_1.loc48: Core.IntLiteral = int_value 1 [template = constants.%int_1]
 // CHECK:STDOUT:   %Run2.ref.loc57: %Run2.type = name_ref Run2, file.%Run2.decl [template = constants.%Run2]
-// CHECK:STDOUT:   %Run2.ref.loc64: %Run2.type = name_ref Run2, file.%Run2.decl [template = constants.%Run2]
-// CHECK:STDOUT:   %int_0.loc64: Core.IntLiteral = int_value 0 [template = constants.%int_0]
+// CHECK:STDOUT:   %Run2.ref.loc65: %Run2.type = name_ref Run2, file.%Run2.decl [template = constants.%Run2]
+// CHECK:STDOUT:   %int_0.loc65: Core.IntLiteral = int_value 0 [template = constants.%int_0]
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/function/call/fail_param_type.carbon b/toolchain/check/testdata/function/call/fail_param_type.carbon
index 6eb2c15fd993..397cb7bb69ec 100644
--- a/toolchain/check/testdata/function/call/fail_param_type.carbon
+++ b/toolchain/check/testdata/function/call/fail_param_type.carbon
@@ -11,15 +11,16 @@
 fn G(a: i32) {}
 
 fn F() {
-  // CHECK:STDERR: fail_param_type.carbon:[[@LINE+9]]:5: error: cannot implicitly convert from `f64` to `i32` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_param_type.carbon:[[@LINE+10]]:5: error: cannot implicitly convert from `f64` to `i32` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   G(1.0);
   // CHECK:STDERR:     ^~~
-  // CHECK:STDERR: fail_param_type.carbon:[[@LINE+6]]:5: note: type `f64` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR: fail_param_type.carbon:[[@LINE+7]]:5: note: type `f64` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]
   // CHECK:STDERR:   G(1.0);
   // CHECK:STDERR:     ^~~
   // CHECK:STDERR: fail_param_type.carbon:[[@LINE-9]]:6: note: initializing function parameter [InCallToFunctionParam]
   // CHECK:STDERR: fn G(a: i32) {}
   // CHECK:STDERR:      ^~~~~~
+  // CHECK:STDERR:
   G(1.0);
 }
 
@@ -75,7 +76,7 @@ fn F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %G.ref: %G.type = name_ref G, file.%G.decl [template = constants.%G]
 // CHECK:STDOUT:   %float: f64 = float_literal 1 [template = constants.%float]
-// CHECK:STDOUT:   %.loc23: %i32 = converted %float, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc24: %i32 = converted %float, <error> [template = <error>]
 // CHECK:STDOUT:   %G.call: init %empty_tuple.type = call %G.ref(<error>)
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/function/call/fail_return_type_mismatch.carbon b/toolchain/check/testdata/function/call/fail_return_type_mismatch.carbon
index 61bc2bde3e25..cafdeefba49d 100644
--- a/toolchain/check/testdata/function/call/fail_return_type_mismatch.carbon
+++ b/toolchain/check/testdata/function/call/fail_return_type_mismatch.carbon
@@ -11,12 +11,13 @@
 fn Foo() -> f64 { return 1.0; }
 
 fn Run() {
-  // CHECK:STDERR: fail_return_type_mismatch.carbon:[[@LINE+6]]:3: error: cannot implicitly convert from `f64` to `i32` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_return_type_mismatch.carbon:[[@LINE+7]]:3: error: cannot implicitly convert from `f64` to `i32` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   var x: i32 = Foo();
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~
-  // CHECK:STDERR: fail_return_type_mismatch.carbon:[[@LINE+3]]:3: note: type `f64` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR: fail_return_type_mismatch.carbon:[[@LINE+4]]:3: note: type `f64` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]
   // CHECK:STDERR:   var x: i32 = Foo();
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   var x: i32 = Foo();
 }
 
@@ -78,7 +79,7 @@ fn Run() {
 // CHECK:STDOUT:   %x: ref %i32 = bind_name x, %x.var
 // CHECK:STDOUT:   %Foo.ref: %Foo.type = name_ref Foo, file.%Foo.decl [template = constants.%Foo]
 // CHECK:STDOUT:   %Foo.call: init f64 = call %Foo.ref()
-// CHECK:STDOUT:   %.loc20: %i32 = converted %Foo.call, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc21: %i32 = converted %Foo.call, <error> [template = <error>]
 // CHECK:STDOUT:   assign %x.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/function/call/no_prelude/fail_explicit_self_param.carbon b/toolchain/check/testdata/function/call/no_prelude/fail_explicit_self_param.carbon
index c2c120546314..5f378409c561 100644
--- a/toolchain/check/testdata/function/call/no_prelude/fail_explicit_self_param.carbon
+++ b/toolchain/check/testdata/function/call/no_prelude/fail_explicit_self_param.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/call/no_prelude/fail_explicit_self_param.carbon
 
-// CHECK:STDERR: fail_explicit_self_param.carbon:[[@LINE+3]]:6: error: `self` can only be declared in an implicit parameter list [SelfOutsideImplicitParamList]
+// CHECK:STDERR: fail_explicit_self_param.carbon:[[@LINE+4]]:6: error: `self` can only be declared in an implicit parameter list [SelfOutsideImplicitParamList]
 // CHECK:STDERR: fn F(self: ());
 // CHECK:STDERR:      ^~~~~~~~
+// CHECK:STDERR:
 fn F(self: ());
 
 fn Run() {
@@ -38,9 +39,9 @@ fn Run() {
 // CHECK:STDOUT:     %self.param_patt: %empty_tuple.type = value_param_pattern %self.patt, runtime_param0
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %self.param: %empty_tuple.type = value_param runtime_param0
-// CHECK:STDOUT:     %.loc14_13.1: type = splice_block %.loc14_13.3 [template = constants.%empty_tuple.type] {
-// CHECK:STDOUT:       %.loc14_13.2: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:       %.loc14_13.3: type = converted %.loc14_13.2, constants.%empty_tuple.type [template = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %.loc15_13.1: type = splice_block %.loc15_13.3 [template = constants.%empty_tuple.type] {
+// CHECK:STDOUT:       %.loc15_13.2: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:       %.loc15_13.3: type = converted %.loc15_13.2, constants.%empty_tuple.type [template = constants.%empty_tuple.type]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %self: %empty_tuple.type = bind_name self, %self.param
 // CHECK:STDOUT:   }
@@ -52,10 +53,10 @@ fn Run() {
 // CHECK:STDOUT: fn @Run() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %F.ref: %F.type = name_ref F, file.%F.decl [template = constants.%F]
-// CHECK:STDOUT:   %.loc17_6.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:   %.loc18_6.1: %empty_tuple.type = tuple_literal ()
 // CHECK:STDOUT:   %empty_tuple: %empty_tuple.type = tuple_value () [template = constants.%empty_tuple]
-// CHECK:STDOUT:   %.loc17_6.2: %empty_tuple.type = converted %.loc17_6.1, %empty_tuple [template = constants.%empty_tuple]
-// CHECK:STDOUT:   %F.call: init %empty_tuple.type = call %F.ref(%.loc17_6.2)
+// CHECK:STDOUT:   %.loc18_6.2: %empty_tuple.type = converted %.loc18_6.1, %empty_tuple [template = constants.%empty_tuple]
+// CHECK:STDOUT:   %F.call: init %empty_tuple.type = call %F.ref(%.loc18_6.2)
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/function/call/no_prelude/fail_runtime_implicit_param.carbon b/toolchain/check/testdata/function/call/no_prelude/fail_runtime_implicit_param.carbon
index 9cce73b8d801..0c4dc22e72c8 100644
--- a/toolchain/check/testdata/function/call/no_prelude/fail_runtime_implicit_param.carbon
+++ b/toolchain/check/testdata/function/call/no_prelude/fail_runtime_implicit_param.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/call/no_prelude/fail_runtime_implicit_param.carbon
 
-// CHECK:STDERR: fail_runtime_implicit_param.carbon:[[@LINE+3]]:6: error: implicit parameters of functions must be constant or `self` [ImplictParamMustBeConstant]
+// CHECK:STDERR: fail_runtime_implicit_param.carbon:[[@LINE+4]]:6: error: implicit parameters of functions must be constant or `self` [ImplictParamMustBeConstant]
 // CHECK:STDERR: fn F[s: ()]();
 // CHECK:STDERR:      ^~~~~
+// CHECK:STDERR:
 fn F[s: ()]();
 
 fn Run() {
diff --git a/toolchain/check/testdata/function/declaration/fail_param_in_type.carbon b/toolchain/check/testdata/function/declaration/fail_param_in_type.carbon
index b2c43edd3599..f0f0ba451c55 100644
--- a/toolchain/check/testdata/function/declaration/fail_param_in_type.carbon
+++ b/toolchain/check/testdata/function/declaration/fail_param_in_type.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/fail_param_in_type.carbon
 
-// CHECK:STDERR: fail_param_in_type.carbon:[[@LINE+3]]:23: error: array bound is not a constant [InvalidArrayExpr]
+// CHECK:STDERR: fail_param_in_type.carbon:[[@LINE+4]]:23: error: array bound is not a constant [InvalidArrayExpr]
 // CHECK:STDERR: fn F(n: i32, a: [i32; n]*);
 // CHECK:STDERR:                       ^
+// CHECK:STDERR:
 fn F(n: i32, a: [i32; n]*);
 
 // CHECK:STDOUT: --- fail_param_in_type.carbon
@@ -43,15 +44,15 @@ fn F(n: i32, a: [i32; n]*);
 // CHECK:STDOUT:     %a.param_patt: <error> = value_param_pattern %a.patt, runtime_param1
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %n.param: %i32 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc14_9: type = splice_block %i32.loc14_9 [template = constants.%i32] {
-// CHECK:STDOUT:       %int_32.loc14_9: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:       %i32.loc14_9: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:     %.loc15_9: type = splice_block %i32.loc15_9 [template = constants.%i32] {
+// CHECK:STDOUT:       %int_32.loc15_9: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:       %i32.loc15_9: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %n: %i32 = bind_name n, %n.param
 // CHECK:STDOUT:     %a.param: <error> = value_param runtime_param1
-// CHECK:STDOUT:     %.loc14_25: type = splice_block %ptr [template = <error>] {
-// CHECK:STDOUT:       %int_32.loc14_18: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:       %i32.loc14_18: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:     %.loc15_25: type = splice_block %ptr [template = <error>] {
+// CHECK:STDOUT:       %int_32.loc15_18: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:       %i32.loc15_18: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
 // CHECK:STDOUT:       %n.ref: %i32 = name_ref n, %n
 // CHECK:STDOUT:       %ptr: type = ptr_type <error> [template = <error>]
 // CHECK:STDOUT:     }
diff --git a/toolchain/check/testdata/function/declaration/fail_param_redecl.carbon b/toolchain/check/testdata/function/declaration/fail_param_redecl.carbon
index 1b58c053becb..bb46c2aed642 100644
--- a/toolchain/check/testdata/function/declaration/fail_param_redecl.carbon
+++ b/toolchain/check/testdata/function/declaration/fail_param_redecl.carbon
@@ -8,12 +8,13 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/fail_param_redecl.carbon
 
-// CHECK:STDERR: fail_param_redecl.carbon:[[@LINE+6]]:14: error: duplicate name being declared in the same scope [NameDeclDuplicate]
+// CHECK:STDERR: fail_param_redecl.carbon:[[@LINE+7]]:14: error: duplicate name being declared in the same scope [NameDeclDuplicate]
 // CHECK:STDERR: fn F(n: i32, n: i32);
 // CHECK:STDERR:              ^
-// CHECK:STDERR: fail_param_redecl.carbon:[[@LINE+3]]:6: note: name is previously declared here [NameDeclPrevious]
+// CHECK:STDERR: fail_param_redecl.carbon:[[@LINE+4]]:6: note: name is previously declared here [NameDeclPrevious]
 // CHECK:STDERR: fn F(n: i32, n: i32);
 // CHECK:STDERR:      ^
+// CHECK:STDERR:
 fn F(n: i32, n: i32);
 
 // CHECK:STDOUT: --- fail_param_redecl.carbon
@@ -40,25 +41,25 @@ fn F(n: i32, n: i32);
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %Core.import = import Core
 // CHECK:STDOUT:   %F.decl: %F.type = fn_decl @F [template = constants.%F] {
-// CHECK:STDOUT:     %n.patt.loc17_6: %i32 = binding_pattern n
-// CHECK:STDOUT:     %n.param_patt.loc17_7: %i32 = value_param_pattern %n.patt.loc17_6, runtime_param0
-// CHECK:STDOUT:     %n.patt.loc17_14: %i32 = binding_pattern n
-// CHECK:STDOUT:     %n.param_patt.loc17_15: %i32 = value_param_pattern %n.patt.loc17_14, runtime_param1
+// CHECK:STDOUT:     %n.patt.loc18_6: %i32 = binding_pattern n
+// CHECK:STDOUT:     %n.param_patt.loc18_7: %i32 = value_param_pattern %n.patt.loc18_6, runtime_param0
+// CHECK:STDOUT:     %n.patt.loc18_14: %i32 = binding_pattern n
+// CHECK:STDOUT:     %n.param_patt.loc18_15: %i32 = value_param_pattern %n.patt.loc18_14, runtime_param1
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %n.param.loc17_7: %i32 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc17_9: type = splice_block %i32.loc17_9 [template = constants.%i32] {
-// CHECK:STDOUT:       %int_32.loc17_9: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:       %i32.loc17_9: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:     %n.param.loc18_7: %i32 = value_param runtime_param0
+// CHECK:STDOUT:     %.loc18_9: type = splice_block %i32.loc18_9 [template = constants.%i32] {
+// CHECK:STDOUT:       %int_32.loc18_9: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:       %i32.loc18_9: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
 // CHECK:STDOUT:     }
-// CHECK:STDOUT:     %n.loc17_6: %i32 = bind_name n, %n.param.loc17_7
-// CHECK:STDOUT:     %n.param.loc17_15: %i32 = value_param runtime_param1
-// CHECK:STDOUT:     %.loc17_17: type = splice_block %i32.loc17_17 [template = constants.%i32] {
-// CHECK:STDOUT:       %int_32.loc17_17: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:       %i32.loc17_17: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:     %n.loc18_6: %i32 = bind_name n, %n.param.loc18_7
+// CHECK:STDOUT:     %n.param.loc18_15: %i32 = value_param runtime_param1
+// CHECK:STDOUT:     %.loc18_17: type = splice_block %i32.loc18_17 [template = constants.%i32] {
+// CHECK:STDOUT:       %int_32.loc18_17: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:       %i32.loc18_17: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
 // CHECK:STDOUT:     }
-// CHECK:STDOUT:     %n.loc17_14: %i32 = bind_name n, %n.param.loc17_15
+// CHECK:STDOUT:     %n.loc18_14: %i32 = bind_name n, %n.param.loc18_15
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @F(%n.param_patt.loc17_7: %i32, %n.param_patt.loc17_15: %i32);
+// CHECK:STDOUT: fn @F(%n.param_patt.loc18_7: %i32, %n.param_patt.loc18_15: %i32);
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/function/declaration/import.carbon b/toolchain/check/testdata/function/declaration/import.carbon
index e547d25a2a51..b8c2357d126a 100644
--- a/toolchain/check/testdata/function/declaration/import.carbon
+++ b/toolchain/check/testdata/function/declaration/import.carbon
@@ -190,50 +190,51 @@ var e: () = NS.E();
 
 library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+44]]:1: in import [InImport]
+// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+45]]:1: in import [InImport]
 // CHECK:STDERR: api.carbon:4:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
 // CHECK:STDERR: fn A();
 // CHECK:STDERR: ^~~~~~~
-// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+40]]:1: in import [InImport]
+// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+41]]:1: in import [InImport]
 // CHECK:STDERR: extern_api.carbon:4:1: note: name is previously declared here [NameDeclPrevious]
 // CHECK:STDERR: extern library "redecl_extern_api" fn A();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+35]]:1: in import [InImport]
+// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+36]]:1: in import [InImport]
 // CHECK:STDERR: api.carbon:5:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
 // CHECK:STDERR: fn B(b: i32) -> i32;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+31]]:1: in import [InImport]
+// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+32]]:1: in import [InImport]
 // CHECK:STDERR: extern_api.carbon:5:1: note: name is previously declared here [NameDeclPrevious]
 // CHECK:STDERR: extern library "redecl_extern_api" fn B(b: i32) -> i32;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+26]]:1: in import [InImport]
+// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+27]]:1: in import [InImport]
 // CHECK:STDERR: api.carbon:6:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
 // CHECK:STDERR: fn C(c: (i32,)) -> {.c: i32};
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+22]]:1: in import [InImport]
+// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+23]]:1: in import [InImport]
 // CHECK:STDERR: extern_api.carbon:6:1: note: name is previously declared here [NameDeclPrevious]
 // CHECK:STDERR: extern library "redecl_extern_api" fn C(c: (i32,)) -> {.c: i32};
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+17]]:1: in import [InImport]
+// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+18]]:1: in import [InImport]
 // CHECK:STDERR: api.carbon:7:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
 // CHECK:STDERR: extern fn D();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
-// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+13]]:1: in import [InImport]
+// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+14]]:1: in import [InImport]
 // CHECK:STDERR: extern_api.carbon:7:1: note: name is previously declared here [NameDeclPrevious]
 // CHECK:STDERR: extern library "redecl_extern_api" fn D();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+8]]:1: in import [InImport]
+// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+9]]:1: in import [InImport]
 // CHECK:STDERR: api.carbon:10:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
 // CHECK:STDERR: fn NS.E();
 // CHECK:STDERR: ^~~~~~~~~~
-// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+4]]:1: in import [InImport]
+// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+5]]:1: in import [InImport]
 // CHECK:STDERR: extern_api.carbon:10:1: note: name is previously declared here [NameDeclPrevious]
 // CHECK:STDERR: extern library "redecl_extern_api" fn NS.E();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 import library "extern_api";
 import library "api";
 
@@ -1081,27 +1082,27 @@ import library "extern_api";
 // CHECK:STDOUT:   %A.call: init %empty_tuple.type = call %A.ref()
 // CHECK:STDOUT:   assign file.%a.var, %A.call
 // CHECK:STDOUT:   %B.ref: %B.type = name_ref B, imports.%import_ref.54c [template = constants.%B]
-// CHECK:STDOUT:   %int_1.loc52: Core.IntLiteral = int_value 1 [template = constants.%int_1.5b8]
-// CHECK:STDOUT:   %impl.elem0.loc52: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
-// CHECK:STDOUT:   %Convert.bound.loc52: <bound method> = bound_method %int_1.loc52, %impl.elem0.loc52 [template = constants.%Convert.bound]
-// CHECK:STDOUT:   %Convert.specific_fn.loc52: <specific function> = specific_function %Convert.bound.loc52, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn]
-// CHECK:STDOUT:   %int.convert_checked.loc52: init %i32 = call %Convert.specific_fn.loc52(%int_1.loc52) [template = constants.%int_1.5d2]
-// CHECK:STDOUT:   %.loc52_16.1: %i32 = value_of_initializer %int.convert_checked.loc52 [template = constants.%int_1.5d2]
-// CHECK:STDOUT:   %.loc52_16.2: %i32 = converted %int_1.loc52, %.loc52_16.1 [template = constants.%int_1.5d2]
-// CHECK:STDOUT:   %B.call: init %i32 = call %B.ref(%.loc52_16.2)
-// CHECK:STDOUT:   assign file.%b.var, %B.call
-// CHECK:STDOUT:   %C.ref: %C.type = name_ref C, imports.%import_ref.94c0 [template = constants.%C]
 // CHECK:STDOUT:   %int_1.loc53: Core.IntLiteral = int_value 1 [template = constants.%int_1.5b8]
-// CHECK:STDOUT:   %.loc53_25.1: %tuple.type.985 = tuple_literal (%int_1.loc53)
 // CHECK:STDOUT:   %impl.elem0.loc53: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
 // CHECK:STDOUT:   %Convert.bound.loc53: <bound method> = bound_method %int_1.loc53, %impl.elem0.loc53 [template = constants.%Convert.bound]
 // CHECK:STDOUT:   %Convert.specific_fn.loc53: <specific function> = specific_function %Convert.bound.loc53, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn]
 // CHECK:STDOUT:   %int.convert_checked.loc53: init %i32 = call %Convert.specific_fn.loc53(%int_1.loc53) [template = constants.%int_1.5d2]
-// CHECK:STDOUT:   %.loc53_25.2: %i32 = value_of_initializer %int.convert_checked.loc53 [template = constants.%int_1.5d2]
-// CHECK:STDOUT:   %.loc53_25.3: %i32 = converted %int_1.loc53, %.loc53_25.2 [template = constants.%int_1.5d2]
-// CHECK:STDOUT:   %tuple: %tuple.type.a1c = tuple_value (%.loc53_25.3) [template = constants.%tuple]
-// CHECK:STDOUT:   %.loc53_25.4: %tuple.type.a1c = converted %.loc53_25.1, %tuple [template = constants.%tuple]
-// CHECK:STDOUT:   %C.call: init %struct_type.c = call %C.ref(%.loc53_25.4)
+// CHECK:STDOUT:   %.loc53_16.1: %i32 = value_of_initializer %int.convert_checked.loc53 [template = constants.%int_1.5d2]
+// CHECK:STDOUT:   %.loc53_16.2: %i32 = converted %int_1.loc53, %.loc53_16.1 [template = constants.%int_1.5d2]
+// CHECK:STDOUT:   %B.call: init %i32 = call %B.ref(%.loc53_16.2)
+// CHECK:STDOUT:   assign file.%b.var, %B.call
+// CHECK:STDOUT:   %C.ref: %C.type = name_ref C, imports.%import_ref.94c0 [template = constants.%C]
+// CHECK:STDOUT:   %int_1.loc54: Core.IntLiteral = int_value 1 [template = constants.%int_1.5b8]
+// CHECK:STDOUT:   %.loc54_25.1: %tuple.type.985 = tuple_literal (%int_1.loc54)
+// CHECK:STDOUT:   %impl.elem0.loc54: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
+// CHECK:STDOUT:   %Convert.bound.loc54: <bound method> = bound_method %int_1.loc54, %impl.elem0.loc54 [template = constants.%Convert.bound]
+// CHECK:STDOUT:   %Convert.specific_fn.loc54: <specific function> = specific_function %Convert.bound.loc54, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn]
+// CHECK:STDOUT:   %int.convert_checked.loc54: init %i32 = call %Convert.specific_fn.loc54(%int_1.loc54) [template = constants.%int_1.5d2]
+// CHECK:STDOUT:   %.loc54_25.2: %i32 = value_of_initializer %int.convert_checked.loc54 [template = constants.%int_1.5d2]
+// CHECK:STDOUT:   %.loc54_25.3: %i32 = converted %int_1.loc54, %.loc54_25.2 [template = constants.%int_1.5d2]
+// CHECK:STDOUT:   %tuple: %tuple.type.a1c = tuple_value (%.loc54_25.3) [template = constants.%tuple]
+// CHECK:STDOUT:   %.loc54_25.4: %tuple.type.a1c = converted %.loc54_25.1, %tuple [template = constants.%tuple]
+// CHECK:STDOUT:   %C.call: init %struct_type.c = call %C.ref(%.loc54_25.4)
 // CHECK:STDOUT:   assign file.%c.var, %C.call
 // CHECK:STDOUT:   %D.ref: %D.type = name_ref D, imports.%import_ref.5f5 [template = constants.%D]
 // CHECK:STDOUT:   %D.call: init %empty_tuple.type = call %D.ref()
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/extern.carbon b/toolchain/check/testdata/function/declaration/no_prelude/extern.carbon
index f212ba75598b..f48ad0f42ae0 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/extern.carbon
+++ b/toolchain/check/testdata/function/declaration/no_prelude/extern.carbon
@@ -71,13 +71,14 @@ library "[[@TEST_NAME]]";
 
 import library "basic";
 
-// CHECK:STDERR: fail_extern_library_in_importer.carbon:[[@LINE+7]]:1: error: cannot declare imported `fn F` as `extern library` [ExternLibraryInImporter]
+// CHECK:STDERR: fail_extern_library_in_importer.carbon:[[@LINE+8]]:1: error: cannot declare imported `fn F` as `extern library` [ExternLibraryInImporter]
 // CHECK:STDERR: extern library "basic" fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_extern_library_in_importer.carbon:[[@LINE-5]]:1: in import [InImport]
 // CHECK:STDERR: basic.carbon:4:1: note: previously declared here [RedeclPrevDecl]
 // CHECK:STDERR: extern fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
+// CHECK:STDERR:
 extern library "basic" fn F();
 
 // CHECK:STDOUT: --- basic.carbon
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/extern_library.carbon b/toolchain/check/testdata/function/declaration/no_prelude/extern_library.carbon
index 3557e6fc36d0..bff87d6c4bae 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/extern_library.carbon
+++ b/toolchain/check/testdata/function/declaration/no_prelude/extern_library.carbon
@@ -150,9 +150,10 @@ extern library "extern_of_import" fn F();
 
 library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_extern_library_on_definition.carbon:[[@LINE+3]]:1: error: a library cannot be provided for an `extern` modifier on a definition [ExternLibraryOnDefinition]
+// CHECK:STDERR: fail_extern_library_on_definition.carbon:[[@LINE+4]]:1: error: a library cannot be provided for an `extern` modifier on a definition [ExternLibraryOnDefinition]
 // CHECK:STDERR: extern library "extern_library_owner" fn F() {}
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 extern library "extern_library_owner" fn F() {}
 
 // CHECK:STDOUT: --- extern_library.carbon
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/extern_library_for_default.carbon b/toolchain/check/testdata/function/declaration/no_prelude/extern_library_for_default.carbon
index bc5efcdf4f94..b99111e6370e 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/extern_library_for_default.carbon
+++ b/toolchain/check/testdata/function/declaration/no_prelude/extern_library_for_default.carbon
@@ -28,13 +28,14 @@ package Foo library "[[@TEST_NAME]]";
 
 import library default;
 
-// CHECK:STDERR: fail_wrong_library.carbon:[[@LINE+7]]:1: error: declaration in library "wrong_library" doesn't match `extern library` declaration [ExternLibraryIncorrect]
+// CHECK:STDERR: fail_wrong_library.carbon:[[@LINE+8]]:1: error: declaration in library "wrong_library" doesn't match `extern library` declaration [ExternLibraryIncorrect]
 // CHECK:STDERR: extern fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
 // CHECK:STDERR: fail_wrong_library.carbon:[[@LINE-5]]:1: in import [InImport]
 // CHECK:STDERR: default.carbon:4:1: note: previously declared with `extern library` here [ExternLibraryExpected]
 // CHECK:STDERR: extern library "expected" fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 extern fn F();
 
 // CHECK:STDOUT: --- default.carbon
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/extern_library_from_default.carbon b/toolchain/check/testdata/function/declaration/no_prelude/extern_library_from_default.carbon
index d1d53cba42a3..720aa311d84d 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/extern_library_from_default.carbon
+++ b/toolchain/check/testdata/function/declaration/no_prelude/extern_library_from_default.carbon
@@ -26,13 +26,14 @@ library "[[@TEST_NAME]]";
 
 import library "extern_library";
 
-// CHECK:STDERR: fail_wrong_library.carbon:[[@LINE+7]]:1: error: declaration in library "wrong_library" doesn't match `extern library` declaration [ExternLibraryIncorrect]
+// CHECK:STDERR: fail_wrong_library.carbon:[[@LINE+8]]:1: error: declaration in library "wrong_library" doesn't match `extern library` declaration [ExternLibraryIncorrect]
 // CHECK:STDERR: extern fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
 // CHECK:STDERR: fail_wrong_library.carbon:[[@LINE-5]]:1: in import [InImport]
 // CHECK:STDERR: extern_library.carbon:4:1: note: previously declared with `extern library` here [ExternLibraryExpected]
 // CHECK:STDERR: extern library default fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 extern fn F();
 
 // CHECK:STDOUT: --- extern_library.carbon
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/fail_import_incomplete_return.carbon b/toolchain/check/testdata/function/declaration/no_prelude/fail_import_incomplete_return.carbon
index 3545f1709313..07c075df466e 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/fail_import_incomplete_return.carbon
+++ b/toolchain/check/testdata/function/declaration/no_prelude/fail_import_incomplete_return.carbon
@@ -67,7 +67,7 @@ fn CallFAndGIncomplete() {
   // CHECK:STDERR:                    ^~~~
   // CHECK:STDERR:
   ReturnCUnused();
-  // CHECK:STDERR: fail_use_imported.carbon:[[@LINE+11]]:3: error: function returns incomplete type `C` [IncompleteTypeInFunctionReturnType]
+  // CHECK:STDERR: fail_use_imported.carbon:[[@LINE+12]]:3: error: function returns incomplete type `C` [IncompleteTypeInFunctionReturnType]
   // CHECK:STDERR:   ReturnCUsed();
   // CHECK:STDERR:   ^~~~~~~~~~~~~
   // CHECK:STDERR: fail_use_imported.carbon:[[@LINE-19]]:1: in import [InImport]
@@ -78,6 +78,7 @@ fn CallFAndGIncomplete() {
   // CHECK:STDERR: fail_incomplete_return.carbon:8:18: note: return type declared here [IncompleteReturnTypeHere]
   // CHECK:STDERR: fn ReturnCUsed() -> C;
   // CHECK:STDERR:                  ^~~~
+  // CHECK:STDERR:
   ReturnCUsed();
   ReturnDUnused();
   ReturnDUsed();
@@ -232,13 +233,13 @@ fn CallFAndGIncomplete() {
 // CHECK:STDOUT:   %ReturnCUsed.ref: %ReturnCUsed.type = name_ref ReturnCUsed, imports.%import_ref.073 [template = constants.%ReturnCUsed]
 // CHECK:STDOUT:   %ReturnCUsed.call: init <error> = call %ReturnCUsed.ref()
 // CHECK:STDOUT:   %ReturnDUnused.ref: %ReturnDUnused.type = name_ref ReturnDUnused, imports.%import_ref.c58 [template = constants.%ReturnDUnused]
-// CHECK:STDOUT:   %.loc32_17.1: ref %D = temporary_storage
-// CHECK:STDOUT:   %ReturnDUnused.call: init %D = call %ReturnDUnused.ref() to %.loc32_17.1
-// CHECK:STDOUT:   %.loc32_17.2: ref %D = temporary %.loc32_17.1, %ReturnDUnused.call
+// CHECK:STDOUT:   %.loc33_17.1: ref %D = temporary_storage
+// CHECK:STDOUT:   %ReturnDUnused.call: init %D = call %ReturnDUnused.ref() to %.loc33_17.1
+// CHECK:STDOUT:   %.loc33_17.2: ref %D = temporary %.loc33_17.1, %ReturnDUnused.call
 // CHECK:STDOUT:   %ReturnDUsed.ref: %ReturnDUsed.type = name_ref ReturnDUsed, imports.%import_ref.e1f [template = constants.%ReturnDUsed]
-// CHECK:STDOUT:   %.loc33_15.1: ref %D = temporary_storage
-// CHECK:STDOUT:   %ReturnDUsed.call: init %D = call %ReturnDUsed.ref() to %.loc33_15.1
-// CHECK:STDOUT:   %.loc33_15.2: ref %D = temporary %.loc33_15.1, %ReturnDUsed.call
+// CHECK:STDOUT:   %.loc34_15.1: ref %D = temporary_storage
+// CHECK:STDOUT:   %ReturnDUsed.call: init %D = call %ReturnDUsed.ref() to %.loc34_15.1
+// CHECK:STDOUT:   %.loc34_15.2: ref %D = temporary %.loc34_15.1, %ReturnDUsed.call
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/fail_modifiers.carbon b/toolchain/check/testdata/function/declaration/no_prelude/fail_modifiers.carbon
index d8ffb2d2969f..dfc5f612af89 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/fail_modifiers.carbon
+++ b/toolchain/check/testdata/function/declaration/no_prelude/fail_modifiers.carbon
@@ -82,12 +82,13 @@ base fn InvalidModifier();
 // CHECK:STDERR:
 default final virtual fn ModifiersConflict2() {}
 
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+6]]:8: error: `private` must appear before `extern` [ModifierMustAppearBefore]
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+7]]:8: error: `private` must appear before `extern` [ModifierMustAppearBefore]
 // CHECK:STDERR: extern private fn ExternOrderAndConflict() {}
 // CHECK:STDERR:        ^~~~~~~
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+3]]:1: note: `extern` previously appeared here [ModifierPrevious]
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+4]]:1: note: `extern` previously appeared here [ModifierPrevious]
 // CHECK:STDERR: extern private fn ExternOrderAndConflict() {}
 // CHECK:STDERR: ^~~~~~
+// CHECK:STDERR:
 extern private fn ExternOrderAndConflict() {}
 
 // CHECK:STDOUT: --- fail_modifiers.carbon
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/fail_pattern_in_signature.carbon b/toolchain/check/testdata/function/declaration/no_prelude/fail_pattern_in_signature.carbon
index 00f1d603d405..8a188061935b 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/fail_pattern_in_signature.carbon
+++ b/toolchain/check/testdata/function/declaration/no_prelude/fail_pattern_in_signature.carbon
@@ -8,13 +8,14 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/no_prelude/fail_pattern_in_signature.carbon
 
-// CHECK:STDERR: fail_pattern_in_signature.carbon:[[@LINE+7]]:6: error: expected name in binding pattern [ExpectedBindingPattern]
+// CHECK:STDERR: fail_pattern_in_signature.carbon:[[@LINE+8]]:6: error: expected name in binding pattern [ExpectedBindingPattern]
 // CHECK:STDERR: fn F((a: {}, b: {}), c: {});
 // CHECK:STDERR:      ^
 // CHECK:STDERR:
-// CHECK:STDERR: fail_pattern_in_signature.carbon:[[@LINE+3]]:6: error: semantics TODO: `handle invalid parse trees in `check`` [SemanticsTodo]
+// CHECK:STDERR: fail_pattern_in_signature.carbon:[[@LINE+4]]:6: error: semantics TODO: `handle invalid parse trees in `check`` [SemanticsTodo]
 // CHECK:STDERR: fn F((a: {}, b: {}), c: {});
 // CHECK:STDERR:      ^
+// CHECK:STDERR:
 fn F((a: {}, b: {}), c: {});
 
 // CHECK:STDOUT: --- fail_pattern_in_signature.carbon
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/fail_redecl.carbon b/toolchain/check/testdata/function/declaration/no_prelude/fail_redecl.carbon
index 79bfc7b086b0..100b83216f35 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/fail_redecl.carbon
+++ b/toolchain/check/testdata/function/declaration/no_prelude/fail_redecl.carbon
@@ -49,12 +49,13 @@ fn D() {}
 fn D();
 
 fn E() {}
-// CHECK:STDERR: fail_redecl.carbon:[[@LINE+6]]:1: error: redefinition of `fn E` [RedeclRedef]
+// CHECK:STDERR: fail_redecl.carbon:[[@LINE+7]]:1: error: redefinition of `fn E` [RedeclRedef]
 // CHECK:STDERR: fn E() {}
 // CHECK:STDERR: ^~~~~~~~
 // CHECK:STDERR: fail_redecl.carbon:[[@LINE-4]]:1: note: previously defined here [RedeclPrevDef]
 // CHECK:STDERR: fn E() {}
 // CHECK:STDERR: ^~~~~~~~
+// CHECK:STDERR:
 fn E() {}
 
 // CHECK:STDOUT: --- fail_redecl.carbon
@@ -124,7 +125,7 @@ fn E() {}
 // CHECK:STDOUT:   %D.decl.loc41: %D.type = fn_decl @D [template = constants.%D] {} {}
 // CHECK:STDOUT:   %D.decl.loc49: %D.type = fn_decl @D [template = constants.%D] {} {}
 // CHECK:STDOUT:   %E.decl: %E.type = fn_decl @E [template = constants.%E] {} {}
-// CHECK:STDOUT:   %.decl.loc58: %.type.b6a92a.2 = fn_decl @.2 [template = constants.%.d852be.2] {} {}
+// CHECK:STDOUT:   %.decl.loc59: %.type.b6a92a.2 = fn_decl @.2 [template = constants.%.d852be.2] {} {}
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @A();
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/fail_todo_no_params.carbon b/toolchain/check/testdata/function/declaration/no_prelude/fail_todo_no_params.carbon
index b9908112d0d2..6ca4c928e150 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/fail_todo_no_params.carbon
+++ b/toolchain/check/testdata/function/declaration/no_prelude/fail_todo_no_params.carbon
@@ -51,9 +51,10 @@ library "[[@TEST_NAME]]";
 // CHECK:STDERR:
 var x:! () = ();
 
-// CHECK:STDERR: fail_invalid_file_generic_regression_test.carbon:[[@LINE+3]]:1: error: semantics TODO: `function with positional parameters` [SemanticsTodo]
+// CHECK:STDERR: fail_invalid_file_generic_regression_test.carbon:[[@LINE+4]]:1: error: semantics TODO: `function with positional parameters` [SemanticsTodo]
 // CHECK:STDERR: fn A {
 // CHECK:STDERR: ^~~~~~
+// CHECK:STDERR:
 fn A {
   A();
 }
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/implicit_import.carbon b/toolchain/check/testdata/function/declaration/no_prelude/implicit_import.carbon
index bb0ea3e1b7e1..4e30031f21a3 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/implicit_import.carbon
+++ b/toolchain/check/testdata/function/declaration/no_prelude/implicit_import.carbon
@@ -54,13 +54,14 @@ fn A();
 
 impl library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_extern_impl.impl.carbon:[[@LINE+7]]:1: error: redeclarations of `fn A` must match use of `extern` [RedeclExternMismatch]
+// CHECK:STDERR: fail_extern_impl.impl.carbon:[[@LINE+8]]:1: error: redeclarations of `fn A` must match use of `extern` [RedeclExternMismatch]
 // CHECK:STDERR: extern fn A();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
 // CHECK:STDERR: fail_extern_impl.impl.carbon:[[@LINE-5]]:6: in import [InImport]
 // CHECK:STDERR: extern_impl.carbon:4:1: note: previously declared here [RedeclPrevDecl]
 // CHECK:STDERR: fn A();
 // CHECK:STDERR: ^~~~~~~
+// CHECK:STDERR:
 extern fn A();
 
 // CHECK:STDOUT: --- basic.carbon
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/name_poisoning.carbon b/toolchain/check/testdata/function/declaration/no_prelude/name_poisoning.carbon
index 833296e60ed5..b9fc7667e226 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/name_poisoning.carbon
+++ b/toolchain/check/testdata/function/declaration/no_prelude/name_poisoning.carbon
@@ -329,9 +329,10 @@ fn F() {
   class B {
     var v: A;
 
-    // CHECK:STDERR: fail_poison_with_lexical_result.carbon:[[@LINE+3]]:5: note: declared here [NameUseBeforeDeclNote]
+    // CHECK:STDERR: fail_poison_with_lexical_result.carbon:[[@LINE+4]]:5: note: declared here [NameUseBeforeDeclNote]
     // CHECK:STDERR:     class A {}
     // CHECK:STDERR:     ^~~~~~~~~
+    // CHECK:STDERR:
     class A {}
   }
 }
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/no_definition_in_impl_file.carbon b/toolchain/check/testdata/function/declaration/no_prelude/no_definition_in_impl_file.carbon
index 8cab2a30cf87..d0f932143eb6 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/no_definition_in_impl_file.carbon
+++ b/toolchain/check/testdata/function/declaration/no_prelude/no_definition_in_impl_file.carbon
@@ -66,9 +66,10 @@ library "[[@TEST_NAME]]";
 
 impl library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_decl_only_in_impl.impl.carbon:[[@LINE+3]]:1: error: no definition found for declaration in impl file [MissingDefinitionInImpl]
+// CHECK:STDERR: fail_decl_only_in_impl.impl.carbon:[[@LINE+4]]:1: error: no definition found for declaration in impl file [MissingDefinitionInImpl]
 // CHECK:STDERR: fn D();
 // CHECK:STDERR: ^~~~~~~
+// CHECK:STDERR:
 fn D();
 
 // CHECK:STDOUT: --- decl_in_api_definition_in_impl.carbon
diff --git a/toolchain/check/testdata/function/definition/import.carbon b/toolchain/check/testdata/function/definition/import.carbon
index 2f307ad8ed6a..f72ac2d4b63a 100644
--- a/toolchain/check/testdata/function/definition/import.carbon
+++ b/toolchain/check/testdata/function/definition/import.carbon
@@ -98,13 +98,14 @@ library "[[@TEST_NAME]]";
 
 import library "fns";
 
-// CHECK:STDERR: fail_mix_extern_decl.carbon:[[@LINE+7]]:1: error: redeclarations of `fn D` must match use of `extern` [RedeclExternMismatch]
+// CHECK:STDERR: fail_mix_extern_decl.carbon:[[@LINE+8]]:1: error: redeclarations of `fn D` must match use of `extern` [RedeclExternMismatch]
 // CHECK:STDERR: extern fn D();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
 // CHECK:STDERR: fail_mix_extern_decl.carbon:[[@LINE-5]]:1: in import [InImport]
 // CHECK:STDERR: fns.carbon:7:1: note: previously declared here [RedeclPrevDecl]
 // CHECK:STDERR: fn D();
 // CHECK:STDERR: ^~~~~~~
+// CHECK:STDERR:
 extern fn D();
 
 fn D() {}
@@ -442,13 +443,13 @@ fn D() {}
 // CHECK:STDOUT:     .A = imports.%import_ref.0c3
 // CHECK:STDOUT:     .B = imports.%import_ref.8cc
 // CHECK:STDOUT:     .C = imports.%import_ref.b05
-// CHECK:STDOUT:     .D = %D.decl.loc13
+// CHECK:STDOUT:     .D = %D.decl.loc14
 // CHECK:STDOUT:     .Core = imports.%Core
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %Core.import = import Core
 // CHECK:STDOUT:   %default.import = import <invalid>
-// CHECK:STDOUT:   %D.decl.loc13: %D.type = fn_decl @D [template = constants.%D] {} {}
-// CHECK:STDOUT:   %D.decl.loc15: %D.type = fn_decl @D [template = constants.%D] {} {}
+// CHECK:STDOUT:   %D.decl.loc14: %D.type = fn_decl @D [template = constants.%D] {} {}
+// CHECK:STDOUT:   %D.decl.loc16: %D.type = fn_decl @D [template = constants.%D] {} {}
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @D() [from "fns.carbon"] {
diff --git a/toolchain/check/testdata/function/definition/import_access.carbon b/toolchain/check/testdata/function/definition/import_access.carbon
index f81adbd19041..a05a6dc17c57 100644
--- a/toolchain/check/testdata/function/definition/import_access.carbon
+++ b/toolchain/check/testdata/function/definition/import_access.carbon
@@ -122,9 +122,10 @@ package Other library "[[@TEST_NAME]]";
 
 import Test library "forward";
 
-// CHECK:STDERR: fail_other_forward.carbon:[[@LINE+3]]:13: error: member name `Forward` not found in `Test` [MemberNameNotFoundInScope]
+// CHECK:STDERR: fail_other_forward.carbon:[[@LINE+4]]:13: error: member name `Forward` not found in `Test` [MemberNameNotFoundInScope]
 // CHECK:STDERR: var f: () = Test.Forward();
 // CHECK:STDERR:             ^~~~~~~~~~~~
+// CHECK:STDERR:
 var f: () = Test.Forward();
 
 // --- todo_fail_private_on_redecl.carbon
diff --git a/toolchain/check/testdata/function/definition/no_prelude/basics.carbon b/toolchain/check/testdata/function/definition/no_prelude/basics.carbon
index 2a337ac0a2a3..19a8740e8bd5 100644
--- a/toolchain/check/testdata/function/definition/no_prelude/basics.carbon
+++ b/toolchain/check/testdata/function/definition/no_prelude/basics.carbon
@@ -13,12 +13,13 @@
 
 class C;
 
-// CHECK:STDERR: fail_incomplete_type.carbon:[[@LINE+6]]:6: error: parameter has incomplete type `C` in function definition [IncompleteTypeInFunctionParam]
+// CHECK:STDERR: fail_incomplete_type.carbon:[[@LINE+7]]:6: error: parameter has incomplete type `C` in function definition [IncompleteTypeInFunctionParam]
 // CHECK:STDERR: fn F(n: C) {}
 // CHECK:STDERR:      ^~~~
 // CHECK:STDERR: fail_incomplete_type.carbon:[[@LINE-5]]:1: note: class was forward declared here [ClassForwardDeclaredHere]
 // CHECK:STDERR: class C;
 // CHECK:STDERR: ^~~~~~~~
+// CHECK:STDERR:
 fn F(n: C) {}
 
 // CHECK:STDOUT: --- fail_incomplete_type.carbon
diff --git a/toolchain/check/testdata/function/definition/no_prelude/extern.carbon b/toolchain/check/testdata/function/definition/no_prelude/extern.carbon
index a74976abe996..bfd7c4953f89 100644
--- a/toolchain/check/testdata/function/definition/no_prelude/extern.carbon
+++ b/toolchain/check/testdata/function/definition/no_prelude/extern.carbon
@@ -105,9 +105,10 @@ library "[[@TEST_NAME]]";
 
 impl library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_in_impl.impl.carbon:[[@LINE+3]]:1: error: `extern` entities must have a declaration in the API file [ExternRequiresDeclInApiFile]
+// CHECK:STDERR: fail_in_impl.impl.carbon:[[@LINE+4]]:1: error: `extern` entities must have a declaration in the API file [ExternRequiresDeclInApiFile]
 // CHECK:STDERR: extern fn F() {}
 // CHECK:STDERR: ^~~~~~~~~~~~~~~
+// CHECK:STDERR:
 extern fn F() {}
 
 // CHECK:STDOUT: --- extern_def.carbon
diff --git a/toolchain/check/testdata/function/definition/no_prelude/extern_library.carbon b/toolchain/check/testdata/function/definition/no_prelude/extern_library.carbon
index 80521c05fcfd..37b97590f2e3 100644
--- a/toolchain/check/testdata/function/definition/no_prelude/extern_library.carbon
+++ b/toolchain/check/testdata/function/definition/no_prelude/extern_library.carbon
@@ -102,9 +102,10 @@ impl library "[[@TEST_NAME]]";
 
 import library "in_impl_extern";
 
-// CHECK:STDERR: fail_in_impl.impl.carbon:[[@LINE+3]]:1: error: `extern` entities must have a declaration in the API file [ExternRequiresDeclInApiFile]
+// CHECK:STDERR: fail_in_impl.impl.carbon:[[@LINE+4]]:1: error: `extern` entities must have a declaration in the API file [ExternRequiresDeclInApiFile]
 // CHECK:STDERR: extern fn F() {}
 // CHECK:STDERR: ^~~~~~~~~~~~~~~
+// CHECK:STDERR:
 extern fn F() {}
 
 // CHECK:STDOUT: --- one_file_extern.carbon
diff --git a/toolchain/check/testdata/function/definition/no_prelude/fail_decl_param_mismatch.carbon b/toolchain/check/testdata/function/definition/no_prelude/fail_decl_param_mismatch.carbon
index 18d73f1ef307..d8f170d90469 100644
--- a/toolchain/check/testdata/function/definition/no_prelude/fail_decl_param_mismatch.carbon
+++ b/toolchain/check/testdata/function/definition/no_prelude/fail_decl_param_mismatch.carbon
@@ -56,12 +56,13 @@ fn J() -> ();
 fn J() {}
 
 fn K() -> ();
-// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE+6]]:1: error: function redeclaration differs because return type is `{}` [FunctionRedeclReturnTypeDiffers]
+// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE+7]]:1: error: function redeclaration differs because return type is `{}` [FunctionRedeclReturnTypeDiffers]
 // CHECK:STDERR: fn K() -> {} { return {}; }
 // CHECK:STDERR: ^~~~~~~~~~~~~~
 // CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE-4]]:1: note: previously declared with return type `()` [FunctionRedeclReturnTypePrevious]
 // CHECK:STDERR: fn K() -> ();
 // CHECK:STDERR: ^~~~~~~~~~~~~
+// CHECK:STDERR:
 fn K() -> {} { return {}; }
 
 // CHECK:STDOUT: --- fail_decl_param_mismatch.carbon
@@ -177,12 +178,12 @@ fn K() -> {} { return {}; }
 // CHECK:STDOUT:     %return.param: ref %empty_tuple.type = out_param runtime_param0
 // CHECK:STDOUT:     %return: ref %empty_tuple.type = return_slot %return.param
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %.decl.loc65: %.type.b6a92a.6 = fn_decl @.6 [template = constants.%.d852be.6] {
+// CHECK:STDOUT:   %.decl.loc66: %.type.b6a92a.6 = fn_decl @.6 [template = constants.%.d852be.6] {
 // CHECK:STDOUT:     %return.patt: %empty_struct_type = return_slot_pattern
 // CHECK:STDOUT:     %return.param_patt: %empty_struct_type = out_param_pattern %return.patt, runtime_param0
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %.loc65_12.1: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:     %.loc65_12.2: type = converted %.loc65_12.1, constants.%empty_struct_type [template = constants.%empty_struct_type]
+// CHECK:STDOUT:     %.loc66_12.1: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:     %.loc66_12.2: type = converted %.loc66_12.1, constants.%empty_struct_type [template = constants.%empty_struct_type]
 // CHECK:STDOUT:     %return.param: ref %empty_struct_type = out_param runtime_param0
 // CHECK:STDOUT:     %return: ref %empty_struct_type = return_slot %return.param
 // CHECK:STDOUT:   }
@@ -230,9 +231,9 @@ fn K() -> {} { return {}; }
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @.6() -> %empty_struct_type {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %.loc65_24: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %.loc66_24: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:   %empty_struct: %empty_struct_type = struct_value () [template = constants.%empty_struct]
-// CHECK:STDOUT:   %.loc65_25: %empty_struct_type = converted %.loc65_24, %empty_struct [template = constants.%empty_struct]
-// CHECK:STDOUT:   return %.loc65_25
+// CHECK:STDOUT:   %.loc66_25: %empty_struct_type = converted %.loc66_24, %empty_struct [template = constants.%empty_struct]
+// CHECK:STDOUT:   return %.loc66_25
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/function/definition/no_prelude/fail_local_decl.carbon b/toolchain/check/testdata/function/definition/no_prelude/fail_local_decl.carbon
index dc4f234a23d6..06b65bcc60bb 100644
--- a/toolchain/check/testdata/function/definition/no_prelude/fail_local_decl.carbon
+++ b/toolchain/check/testdata/function/definition/no_prelude/fail_local_decl.carbon
@@ -40,9 +40,10 @@ fn F() {
   // CHECK:STDERR:   ^~~~~~~
   // CHECK:STDERR:
   private var v: {};
-  // CHECK:STDERR: fail_access.carbon:[[@LINE+3]]:3: error: `protected` not allowed; requires class scope [ModifierProtectedNotAllowed]
+  // CHECK:STDERR: fail_access.carbon:[[@LINE+4]]:3: error: `protected` not allowed; requires class scope [ModifierProtectedNotAllowed]
   // CHECK:STDERR:   protected var w: {};
   // CHECK:STDERR:   ^~~~~~~~~
+  // CHECK:STDERR:
   protected var w: {};
 }
 
diff --git a/toolchain/check/testdata/function/definition/no_prelude/fail_redef.carbon b/toolchain/check/testdata/function/definition/no_prelude/fail_redef.carbon
index 4bf08dcdc632..35035ea7a2c7 100644
--- a/toolchain/check/testdata/function/definition/no_prelude/fail_redef.carbon
+++ b/toolchain/check/testdata/function/definition/no_prelude/fail_redef.carbon
@@ -9,12 +9,13 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/no_prelude/fail_redef.carbon
 
 fn F() {}
-// CHECK:STDERR: fail_redef.carbon:[[@LINE+6]]:1: error: redefinition of `fn F` [RedeclRedef]
+// CHECK:STDERR: fail_redef.carbon:[[@LINE+7]]:1: error: redefinition of `fn F` [RedeclRedef]
 // CHECK:STDERR: fn F() {}
 // CHECK:STDERR: ^~~~~~~~
 // CHECK:STDERR: fail_redef.carbon:[[@LINE-4]]:1: note: previously defined here [RedeclPrevDef]
 // CHECK:STDERR: fn F() {}
 // CHECK:STDERR: ^~~~~~~~
+// CHECK:STDERR:
 fn F() {}
 
 // CHECK:STDOUT: --- fail_redef.carbon
diff --git a/toolchain/check/testdata/function/definition/no_prelude/implicit_import.carbon b/toolchain/check/testdata/function/definition/no_prelude/implicit_import.carbon
index 542baa123d81..1ab7d44c3e9a 100644
--- a/toolchain/check/testdata/function/definition/no_prelude/implicit_import.carbon
+++ b/toolchain/check/testdata/function/definition/no_prelude/implicit_import.carbon
@@ -111,13 +111,14 @@ alias B = A;
 
 impl library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_def_alias.impl.carbon:[[@LINE+7]]:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
+// CHECK:STDERR: fail_def_alias.impl.carbon:[[@LINE+8]]:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
 // CHECK:STDERR: fn B() {}
 // CHECK:STDERR: ^~~~~~~~
 // CHECK:STDERR: fail_def_alias.impl.carbon:[[@LINE-5]]:6: in import [InImport]
 // CHECK:STDERR: def_alias.carbon:5:7: note: name is previously declared here [NameDeclPrevious]
 // CHECK:STDERR: alias B = A;
 // CHECK:STDERR:       ^
+// CHECK:STDERR:
 fn B() {}
 
 // CHECK:STDOUT: --- basic.carbon
diff --git a/toolchain/check/testdata/function/definition/no_prelude/syntactic_merge.carbon b/toolchain/check/testdata/function/definition/no_prelude/syntactic_merge.carbon
index bfaa470e78cd..f49f0bf8d18d 100644
--- a/toolchain/check/testdata/function/definition/no_prelude/syntactic_merge.carbon
+++ b/toolchain/check/testdata/function/definition/no_prelude/syntactic_merge.carbon
@@ -156,16 +156,17 @@ library "[[@TEST_NAME]]";
 class C {}
 
 fn Foo(a: const C);
-// CHECK:STDERR: fail_repeat_const.carbon:[[@LINE+10]]:11: warning: `const` applied repeatedly to the same type has no additional effect [RepeatedConst]
+// CHECK:STDERR: fail_repeat_const.carbon:[[@LINE+11]]:11: warning: `const` applied repeatedly to the same type has no additional effect [RepeatedConst]
 // CHECK:STDERR: fn Foo(a: const (const C)) {}
 // CHECK:STDERR:           ^~~~~~~~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_repeat_const.carbon:[[@LINE+6]]:17: error: redeclaration syntax differs here [RedeclParamSyntaxDiffers]
+// CHECK:STDERR: fail_repeat_const.carbon:[[@LINE+7]]:17: error: redeclaration syntax differs here [RedeclParamSyntaxDiffers]
 // CHECK:STDERR: fn Foo(a: const (const C)) {}
 // CHECK:STDERR:                 ^
 // CHECK:STDERR: fail_repeat_const.carbon:[[@LINE-8]]:17: note: comparing with previous declaration here [RedeclParamSyntaxPrevious]
 // CHECK:STDERR: fn Foo(a: const C);
 // CHECK:STDERR:                 ^
+// CHECK:STDERR:
 fn Foo(a: const (const C)) {}
 
 // CHECK:STDOUT: --- basic.carbon
@@ -823,10 +824,10 @@ fn Foo(a: const (const C)) {}
 // CHECK:STDOUT:     %a.param_patt: %const = value_param_pattern %a.patt, runtime_param0
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %a.param: %const = value_param runtime_param0
-// CHECK:STDOUT:     %.loc17: type = splice_block %const.loc17_11 [template = constants.%const] {
+// CHECK:STDOUT:     %.loc18: type = splice_block %const.loc18_11 [template = constants.%const] {
 // CHECK:STDOUT:       %C.ref: type = name_ref C, file.%C.decl [template = constants.%C]
-// CHECK:STDOUT:       %const.loc17_18: type = const_type %C [template = constants.%const]
-// CHECK:STDOUT:       %const.loc17_11: type = const_type %const [template = constants.%const]
+// CHECK:STDOUT:       %const.loc18_18: type = const_type %C [template = constants.%const]
+// CHECK:STDOUT:       %const.loc18_11: type = const_type %const [template = constants.%const]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: %const = bind_name a, %a.param
 // CHECK:STDOUT:   }
diff --git a/toolchain/check/testdata/function/generic/deduce.carbon b/toolchain/check/testdata/function/generic/deduce.carbon
index 23d917894a8b..eb41ee84e446 100644
--- a/toolchain/check/testdata/function/generic/deduce.carbon
+++ b/toolchain/check/testdata/function/generic/deduce.carbon
@@ -181,12 +181,13 @@ library "[[@TEST_NAME]]";
 fn ImplicitNotDeducible[T:! type](x: T, y: T) -> T;
 
 fn CallImplicitNotDeducible() {
-  // CHECK:STDERR: fail_deduce_inconsistent.carbon:[[@LINE+6]]:3: error: inconsistent deductions for value of generic parameter `T` [DeductionInconsistent]
+  // CHECK:STDERR: fail_deduce_inconsistent.carbon:[[@LINE+7]]:3: error: inconsistent deductions for value of generic parameter `T` [DeductionInconsistent]
   // CHECK:STDERR:   ImplicitNotDeducible(42, {.x = 12});
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   // CHECK:STDERR: fail_deduce_inconsistent.carbon:[[@LINE-6]]:1: note: while deducing parameters of generic declared here [DeductionGenericHere]
   // CHECK:STDERR: fn ImplicitNotDeducible[T:! type](x: T, y: T) -> T;
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   ImplicitNotDeducible(42, {.x = 12});
 }
 
@@ -1463,7 +1464,7 @@ fn CallImplicitNotDeducible() {
 // CHECK:STDOUT:   %ImplicitNotDeducible.ref: %ImplicitNotDeducible.type = name_ref ImplicitNotDeducible, file.%ImplicitNotDeducible.decl [template = constants.%ImplicitNotDeducible]
 // CHECK:STDOUT:   %int_42: Core.IntLiteral = int_value 42 [template = constants.%int_42]
 // CHECK:STDOUT:   %int_12: Core.IntLiteral = int_value 12 [template = constants.%int_12]
-// CHECK:STDOUT:   %.loc13: %struct_type.x = struct_literal (%int_12)
+// CHECK:STDOUT:   %.loc14: %struct_type.x = struct_literal (%int_12)
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/function/generic/no_prelude/fail_type_param_mismatch.carbon b/toolchain/check/testdata/function/generic/no_prelude/fail_type_param_mismatch.carbon
index b45cbaaa613f..56f2779dae8d 100644
--- a/toolchain/check/testdata/function/generic/no_prelude/fail_type_param_mismatch.carbon
+++ b/toolchain/check/testdata/function/generic/no_prelude/fail_type_param_mismatch.carbon
@@ -10,9 +10,10 @@
 
 fn F(T:! type, U:! type) {
   var p: T*;
-  // CHECK:STDERR: fail_type_param_mismatch.carbon:[[@LINE+3]]:3: error: `Core.ImplicitAs` implicitly referenced here, but package `Core` not found [CoreNotFound]
+  // CHECK:STDERR: fail_type_param_mismatch.carbon:[[@LINE+4]]:3: error: `Core.ImplicitAs` implicitly referenced here, but package `Core` not found [CoreNotFound]
   // CHECK:STDERR:   let n: U = *p;
   // CHECK:STDERR:   ^~~~~~~~~~~~~~
+  // CHECK:STDERR:
   let n: U = *p;
 }
 
@@ -56,16 +57,16 @@ fn F(T:! type, U:! type) {
 // CHECK:STDOUT: !definition:
 // CHECK:STDOUT:   %ptr: type = ptr_type @F.%T.loc11_6.2 (%T) [symbolic = %ptr (constants.%ptr)]
 // CHECK:STDOUT:   %require_complete.loc12: <witness> = require_complete_type @F.%ptr (%ptr) [symbolic = %require_complete.loc12 (constants.%require_complete.6e5)]
-// CHECK:STDOUT:   %require_complete.loc16: <witness> = require_complete_type @F.%U.loc11_16.2 (%U) [symbolic = %require_complete.loc16 (constants.%require_complete.b54)]
+// CHECK:STDOUT:   %require_complete.loc17: <witness> = require_complete_type @F.%U.loc11_16.2 (%U) [symbolic = %require_complete.loc17 (constants.%require_complete.b54)]
 // CHECK:STDOUT:
 // CHECK:STDOUT:   fn(%T.param_patt: type, %U.param_patt: type) {
 // CHECK:STDOUT:   !entry:
 // CHECK:STDOUT:     %p.var: ref @F.%ptr (%ptr) = var p
 // CHECK:STDOUT:     %p: ref @F.%ptr (%ptr) = bind_name p, %p.var
 // CHECK:STDOUT:     %p.ref: ref @F.%ptr (%ptr) = name_ref p, %p
-// CHECK:STDOUT:     %.loc16_15: @F.%ptr (%ptr) = bind_value %p.ref
-// CHECK:STDOUT:     %.loc16_14: ref @F.%T.loc11_6.2 (%T) = deref %.loc16_15
-// CHECK:STDOUT:     %.loc16_16: @F.%U.loc11_16.2 (%U) = converted %.loc16_14, <error> [template = <error>]
+// CHECK:STDOUT:     %.loc17_15: @F.%ptr (%ptr) = bind_value %p.ref
+// CHECK:STDOUT:     %.loc17_14: ref @F.%T.loc11_6.2 (%T) = deref %.loc17_15
+// CHECK:STDOUT:     %.loc17_16: @F.%U.loc11_16.2 (%U) = converted %.loc17_14, <error> [template = <error>]
 // CHECK:STDOUT:     %n: @F.%U.loc11_16.2 (%U) = bind_name n, <error>
 // CHECK:STDOUT:     return
 // CHECK:STDOUT:   }
diff --git a/toolchain/check/testdata/function/generic/redeclare.carbon b/toolchain/check/testdata/function/generic/redeclare.carbon
index a1e34d177697..a107958b2a49 100644
--- a/toolchain/check/testdata/function/generic/redeclare.carbon
+++ b/toolchain/check/testdata/function/generic/redeclare.carbon
@@ -80,12 +80,13 @@ fn F(T:! type, U:! type) -> T*;
 // CHECK:STDERR:      ^~~~~~~~
 // CHECK:STDERR:
 fn F(U:! type, T:! type) -> U* {
-  // CHECK:STDERR: fail_rename.carbon:[[@LINE+6]]:10: error: 1 argument passed to function expecting 2 arguments [CallArgCountMismatch]
+  // CHECK:STDERR: fail_rename.carbon:[[@LINE+7]]:10: error: 1 argument passed to function expecting 2 arguments [CallArgCountMismatch]
   // CHECK:STDERR:   return F(T);
   // CHECK:STDERR:          ^~~~
   // CHECK:STDERR: fail_rename.carbon:[[@LINE-13]]:1: note: calling function declared here [InCallToEntity]
   // CHECK:STDERR: fn F(T:! type, U:! type) -> T*;
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   return F(T);
 }
 
diff --git a/toolchain/check/testdata/function/generic/resolve_used.carbon b/toolchain/check/testdata/function/generic/resolve_used.carbon
index 856c7a6e9d09..bb0073289895 100644
--- a/toolchain/check/testdata/function/generic/resolve_used.carbon
+++ b/toolchain/check/testdata/function/generic/resolve_used.carbon
@@ -27,9 +27,10 @@ fn ErrorIfNIsZero(N:! Core.IntLiteral()) {
 }
 
 fn CallNegative() {
-  // CHECK:STDERR: fail_todo_call_monomorphization_error.carbon:[[@LINE+3]]:3: note: in `ErrorIfNIsZero(0)` used here [ResolvingSpecificHere]
+  // CHECK:STDERR: fail_todo_call_monomorphization_error.carbon:[[@LINE+4]]:3: note: in `ErrorIfNIsZero(0)` used here [ResolvingSpecificHere]
   // CHECK:STDERR:   ErrorIfNIsZero(0);
   // CHECK:STDERR:   ^~~~~~~~~~~~~~
+  // CHECK:STDERR:
   ErrorIfNIsZero(0);
 }
 
diff --git a/toolchain/check/testdata/function/generic/undefined.carbon b/toolchain/check/testdata/function/generic/undefined.carbon
index e5f20492ce84..779f7d31a333 100644
--- a/toolchain/check/testdata/function/generic/undefined.carbon
+++ b/toolchain/check/testdata/function/generic/undefined.carbon
@@ -41,12 +41,13 @@ library "[[@TEST_NAME]]";
 fn Undefined[T:! type](x: T) -> T;
 
 fn CallUndefined() -> i32 {
-  // CHECK:STDERR: fail_call_undefined.carbon:[[@LINE+6]]:10: error: use of undefined generic function [MissingGenericFunctionDefinition]
+  // CHECK:STDERR: fail_call_undefined.carbon:[[@LINE+7]]:10: error: use of undefined generic function [MissingGenericFunctionDefinition]
   // CHECK:STDERR:   return Undefined(0 as i32);
   // CHECK:STDERR:          ^~~~~~~~~
   // CHECK:STDERR: fail_call_undefined.carbon:[[@LINE-6]]:1: note: generic function declared here [MissingGenericFunctionDefinitionHere]
   // CHECK:STDERR: fn Undefined[T:! type](x: T) -> T;
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   return Undefined(0 as i32);
 }
 
@@ -374,19 +375,19 @@ fn CallUndefined() -> i32 {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Undefined.ref: %Undefined.type = name_ref Undefined, file.%Undefined.decl [template = constants.%Undefined]
 // CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [template = constants.%int_0.5c6]
-// CHECK:STDOUT:   %int_32.loc13: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:   %i32.loc13: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:   %int_32.loc14: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:   %i32.loc14: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
 // CHECK:STDOUT:   %impl.elem0: %Convert.type.99b = impl_witness_access constants.%impl_witness.882, element0 [template = constants.%Convert.197]
 // CHECK:STDOUT:   %Convert.bound: <bound method> = bound_method %int_0, %impl.elem0 [template = constants.%Convert.bound]
 // CHECK:STDOUT:   %Convert.specific_fn: <specific function> = specific_function %Convert.bound, @Convert.5(constants.%int_32) [template = constants.%Convert.specific_fn]
 // CHECK:STDOUT:   %int.convert_checked: init %i32 = call %Convert.specific_fn(%int_0) [template = constants.%int_0.6a9]
-// CHECK:STDOUT:   %.loc13_22.1: %i32 = value_of_initializer %int.convert_checked [template = constants.%int_0.6a9]
-// CHECK:STDOUT:   %.loc13_22.2: %i32 = converted %int_0, %.loc13_22.1 [template = constants.%int_0.6a9]
+// CHECK:STDOUT:   %.loc14_22.1: %i32 = value_of_initializer %int.convert_checked [template = constants.%int_0.6a9]
+// CHECK:STDOUT:   %.loc14_22.2: %i32 = converted %int_0, %.loc14_22.1 [template = constants.%int_0.6a9]
 // CHECK:STDOUT:   %Undefined.specific_fn: <specific function> = specific_function %Undefined.ref, @Undefined(constants.%i32) [template = constants.%Undefined.specific_fn]
-// CHECK:STDOUT:   %Undefined.call: init %i32 = call %Undefined.specific_fn(%.loc13_22.2)
-// CHECK:STDOUT:   %.loc13_29.1: %i32 = value_of_initializer %Undefined.call
-// CHECK:STDOUT:   %.loc13_29.2: %i32 = converted %Undefined.call, %.loc13_29.1
-// CHECK:STDOUT:   return %.loc13_29.2
+// CHECK:STDOUT:   %Undefined.call: init %i32 = call %Undefined.specific_fn(%.loc14_22.2)
+// CHECK:STDOUT:   %.loc14_29.1: %i32 = value_of_initializer %Undefined.call
+// CHECK:STDOUT:   %.loc14_29.2: %i32 = converted %Undefined.call, %.loc14_29.1
+// CHECK:STDOUT:   return %.loc14_29.2
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @Undefined(constants.%T) {
diff --git a/toolchain/check/testdata/generic/complete_type.carbon b/toolchain/check/testdata/generic/complete_type.carbon
index 4d4b632eb8ad..cfa5444ad084 100644
--- a/toolchain/check/testdata/generic/complete_type.carbon
+++ b/toolchain/check/testdata/generic/complete_type.carbon
@@ -70,9 +70,10 @@ fn F(T:! type) {
   var v: T;
 }
 
-// CHECK:STDERR: fail_incomplete_in_function_at_eof.carbon:[[@LINE+3]]:10: note: in `F(B)` used here [ResolvingSpecificHere]
+// CHECK:STDERR: fail_incomplete_in_function_at_eof.carbon:[[@LINE+4]]:10: note: in `F(B)` used here [ResolvingSpecificHere]
 // CHECK:STDERR: fn G() { F(B); }
 // CHECK:STDERR:          ^
+// CHECK:STDERR:
 fn G() { F(B); }
 
 // CHECK:STDOUT: --- fail_incomplete_in_class.carbon
diff --git a/toolchain/check/testdata/generic/local.carbon b/toolchain/check/testdata/generic/local.carbon
index 545c696acb60..5d2e3507a213 100644
--- a/toolchain/check/testdata/generic/local.carbon
+++ b/toolchain/check/testdata/generic/local.carbon
@@ -25,12 +25,13 @@ library "[[@TEST_NAME]]";
 
 fn F() {
   // TODO: Decide on what behavior we want here. We don't reject the corresponding case outside of a function.
-  // CHECK:STDERR: fail_param_shadows_class.carbon:[[@LINE+6]]:3: error: duplicate name being declared in the same scope [NameDeclDuplicate]
+  // CHECK:STDERR: fail_param_shadows_class.carbon:[[@LINE+7]]:3: error: duplicate name being declared in the same scope [NameDeclDuplicate]
   // CHECK:STDERR:   class C(C:! type) {
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~
-  // CHECK:STDERR: fail_param_shadows_class.carbon:[[@LINE+3]]:11: note: name is previously declared here [NameDeclPrevious]
+  // CHECK:STDERR: fail_param_shadows_class.carbon:[[@LINE+4]]:11: note: name is previously declared here [NameDeclPrevious]
   // CHECK:STDERR:   class C(C:! type) {
   // CHECK:STDERR:           ^
+  // CHECK:STDERR:
   class C(C:! type) {
   }
 }
@@ -186,9 +187,9 @@ class C(C:! type) {
 // CHECK:STDOUT:   %F.decl: %F.type = fn_decl @F [template = constants.%F] {} {}
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: generic class @.1(%C.loc12_11.1: type) {
-// CHECK:STDOUT:   %C.loc12_11.2: type = bind_symbolic_name C, 0 [symbolic = %C.loc12_11.2 (constants.%C)]
-// CHECK:STDOUT:   %C.patt.loc12_11.2: type = symbolic_binding_pattern C, 0 [symbolic = %C.patt.loc12_11.2 (constants.%C.patt)]
+// CHECK:STDOUT: generic class @.1(%C.loc13_11.1: type) {
+// CHECK:STDOUT:   %C.loc13_11.2: type = bind_symbolic_name C, 0 [symbolic = %C.loc13_11.2 (constants.%C)]
+// CHECK:STDOUT:   %C.patt.loc13_11.2: type = symbolic_binding_pattern C, 0 [symbolic = %C.patt.loc13_11.2 (constants.%C.patt)]
 // CHECK:STDOUT:
 // CHECK:STDOUT: !definition:
 // CHECK:STDOUT:
@@ -201,18 +202,18 @@ class C(C:! type) {
 // CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %.decl: %.type = class_decl @.1 [template = constants.%.generic] {
-// CHECK:STDOUT:     %C.patt.loc12_11.1: type = symbolic_binding_pattern C, 0 [symbolic = %C.patt.loc12_11.2 (constants.%C.patt)]
-// CHECK:STDOUT:     %C.param_patt: type = value_param_pattern %C.patt.loc12_11.1, runtime_param<invalid> [symbolic = %C.patt.loc12_11.2 (constants.%C.patt)]
+// CHECK:STDOUT:     %C.patt.loc13_11.1: type = symbolic_binding_pattern C, 0 [symbolic = %C.patt.loc13_11.2 (constants.%C.patt)]
+// CHECK:STDOUT:     %C.param_patt: type = value_param_pattern %C.patt.loc13_11.1, runtime_param<invalid> [symbolic = %C.patt.loc13_11.2 (constants.%C.patt)]
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %C.param: type = value_param runtime_param<invalid>
-// CHECK:STDOUT:     %C.loc12_11.1: type = bind_symbolic_name C, 0, %C.param [symbolic = %C.loc12_11.2 (constants.%C)]
+// CHECK:STDOUT:     %C.loc13_11.1: type = bind_symbolic_name C, 0, %C.param [symbolic = %C.loc13_11.2 (constants.%C)]
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @.1(constants.%C) {
-// CHECK:STDOUT:   %C.loc12_11.2 => constants.%C
-// CHECK:STDOUT:   %C.patt.loc12_11.2 => constants.%C
+// CHECK:STDOUT:   %C.loc13_11.2 => constants.%C
+// CHECK:STDOUT:   %C.patt.loc13_11.2 => constants.%C
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- nonlocal_param_shadows_class.carbon
diff --git a/toolchain/check/testdata/if/fail_reachable_fallthrough.carbon b/toolchain/check/testdata/if/fail_reachable_fallthrough.carbon
index dcd4fae80688..18772de3c492 100644
--- a/toolchain/check/testdata/if/fail_reachable_fallthrough.carbon
+++ b/toolchain/check/testdata/if/fail_reachable_fallthrough.carbon
@@ -34,9 +34,10 @@ fn If3(b: bool) -> i32 {
   if (b) {
     return 1;
   }
-// CHECK:STDERR: fail_reachable_fallthrough.carbon:[[@LINE+3]]:1: error: missing `return` at end of function with declared return type [MissingReturnStatement]
+// CHECK:STDERR: fail_reachable_fallthrough.carbon:[[@LINE+4]]:1: error: missing `return` at end of function with declared return type [MissingReturnStatement]
 // CHECK:STDERR: }
 // CHECK:STDERR: ^
+// CHECK:STDERR:
 }
 
 // CHECK:STDOUT: --- fail_reachable_fallthrough.carbon
diff --git a/toolchain/check/testdata/if/fail_scope.carbon b/toolchain/check/testdata/if/fail_scope.carbon
index beb7901af526..dc4524e13738 100644
--- a/toolchain/check/testdata/if/fail_scope.carbon
+++ b/toolchain/check/testdata/if/fail_scope.carbon
@@ -13,9 +13,10 @@ fn VarScope(b: bool) -> i32 {
     var n: i32 = 2;
     return n;
   }
-  // CHECK:STDERR: fail_scope.carbon:[[@LINE+3]]:10: error: name `n` not found [NameNotFound]
+  // CHECK:STDERR: fail_scope.carbon:[[@LINE+4]]:10: error: name `n` not found [NameNotFound]
   // CHECK:STDERR:   return n;
   // CHECK:STDERR:          ^
+  // CHECK:STDERR:
   return n;
 }
 
@@ -94,7 +95,7 @@ fn VarScope(b: bool) -> i32 {
 // CHECK:STDOUT:   return %.loc14
 // CHECK:STDOUT:
 // CHECK:STDOUT: !if.else:
-// CHECK:STDOUT:   %n.ref.loc19: <error> = name_ref n, <error> [template = <error>]
+// CHECK:STDOUT:   %n.ref.loc20: <error> = name_ref n, <error> [template = <error>]
 // CHECK:STDOUT:   return <error>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/if_expr/fail_not_in_function.carbon b/toolchain/check/testdata/if_expr/fail_not_in_function.carbon
index fd3b13f4ccf8..fe5c3898170c 100644
--- a/toolchain/check/testdata/if_expr/fail_not_in_function.carbon
+++ b/toolchain/check/testdata/if_expr/fail_not_in_function.carbon
@@ -43,9 +43,10 @@ var y: if true then i32 else f64;
 fn F(a: if true then i32 else f64);
 
 class C {
-  // CHECK:STDERR: fail_not_in_function.carbon:[[@LINE+3]]:10: error: semantics TODO: `Control flow expressions are currently only supported inside functions.` [SemanticsTodo]
+  // CHECK:STDERR: fail_not_in_function.carbon:[[@LINE+4]]:10: error: semantics TODO: `Control flow expressions are currently only supported inside functions.` [SemanticsTodo]
   // CHECK:STDERR:   var n: if true then i32 else f64;
   // CHECK:STDERR:          ^~~~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   var n: if true then i32 else f64;
 }
 
@@ -95,7 +96,7 @@ class C {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: class @C {
-// CHECK:STDOUT:   %.loc49: %C.elem = field_decl n, element0 [template]
+// CHECK:STDOUT:   %.loc50: %C.elem = field_decl n, element0 [template]
 // CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %struct_type.n [template = constants.%complete_type.54b]
 // CHECK:STDOUT:   complete_type_witness = %complete_type
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/if_expr/fail_partial_constant.carbon b/toolchain/check/testdata/if_expr/fail_partial_constant.carbon
index 2dc93ce5c039..2bb78a8d9184 100644
--- a/toolchain/check/testdata/if_expr/fail_partial_constant.carbon
+++ b/toolchain/check/testdata/if_expr/fail_partial_constant.carbon
@@ -33,9 +33,10 @@ fn ChosenBranchIsNonConstant(t: type) {
   // CHECK:STDERR:          ^~~~~~~~~~~~~~~~~~~~~~~
   // CHECK:STDERR:
   var v: if true then t else i32 = 1;
-  // CHECK:STDERR: fail_non_constant_result.carbon:[[@LINE+3]]:10: error: cannot evaluate type expression [TypeExprEvaluationFailure]
+  // CHECK:STDERR: fail_non_constant_result.carbon:[[@LINE+4]]:10: error: cannot evaluate type expression [TypeExprEvaluationFailure]
   // CHECK:STDERR:   var w: if false then i32 else t = 1;
   // CHECK:STDERR:          ^~~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   var w: if false then i32 else t = 1;
 }
 
@@ -126,7 +127,7 @@ fn ChosenBranchIsNonConstant(t: type) {
 // CHECK:STDOUT:   assign %v.var, <error>
 // CHECK:STDOUT:   %w.var: ref <error> = var w
 // CHECK:STDOUT:   %w: ref <error> = bind_name w, %w.var
-// CHECK:STDOUT:   %int_1.loc13: Core.IntLiteral = int_value 1 [template = constants.%int_1]
+// CHECK:STDOUT:   %int_1.loc14: Core.IntLiteral = int_value 1 [template = constants.%int_1]
 // CHECK:STDOUT:   assign %w.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/impl/fail_call_invalid.carbon b/toolchain/check/testdata/impl/fail_call_invalid.carbon
index d25a242dfbed..7bff5cff8018 100644
--- a/toolchain/check/testdata/impl/fail_call_invalid.carbon
+++ b/toolchain/check/testdata/impl/fail_call_invalid.carbon
@@ -13,9 +13,10 @@ interface Simple {
 }
 
 impl i32 as Simple {
-  // CHECK:STDERR: fail_call_invalid.carbon:[[@LINE+3]]:14: error: name `Undeclared` not found [NameNotFound]
+  // CHECK:STDERR: fail_call_invalid.carbon:[[@LINE+4]]:14: error: name `Undeclared` not found [NameNotFound]
   // CHECK:STDERR:   fn G[self: Undeclared]();
   // CHECK:STDERR:              ^~~~~~~~~~
+  // CHECK:STDERR:
   fn G[self: Undeclared]();
 }
 
@@ -70,7 +71,7 @@ fn InstanceCall(n: i32) {
 // CHECK:STDOUT:     %n.param_patt: %i32 = value_param_pattern %n.patt, runtime_param0
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %n.param: %i32 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc22: type = splice_block %i32 [template = constants.%i32] {
+// CHECK:STDOUT:     %.loc23: type = splice_block %i32 [template = constants.%i32] {
 // CHECK:STDOUT:       %int_32: Core.IntLiteral = int_value 32 [template = constants.%int_32]
 // CHECK:STDOUT:       %i32: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
 // CHECK:STDOUT:     }
diff --git a/toolchain/check/testdata/impl/fail_extend_impl_forall.carbon b/toolchain/check/testdata/impl/fail_extend_impl_forall.carbon
index 5eb9507258ea..73a4a91b0fa8 100644
--- a/toolchain/check/testdata/impl/fail_extend_impl_forall.carbon
+++ b/toolchain/check/testdata/impl/fail_extend_impl_forall.carbon
@@ -13,9 +13,10 @@ interface GenericInterface(T:! type) {
 }
 
 class C {
-  // CHECK:STDERR: fail_extend_impl_forall.carbon:[[@LINE+3]]:3: error: cannot `extend` a parameterized `impl` [ExtendImplForall]
+  // CHECK:STDERR: fail_extend_impl_forall.carbon:[[@LINE+4]]:3: error: cannot `extend` a parameterized `impl` [ExtendImplForall]
   // CHECK:STDERR:   extend impl forall [T:! type] as GenericInterface(T) {
   // CHECK:STDERR:   ^~~~~~
+  // CHECK:STDERR:
   extend impl forall [T:! type] as GenericInterface(T) {
     fn F(x: T) {}
   }
@@ -100,24 +101,24 @@ class C {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: generic impl @impl(%T.loc19_23.1: type) {
-// CHECK:STDOUT:   %T.loc19_23.2: type = bind_symbolic_name T, 0 [symbolic = %T.loc19_23.2 (constants.%T)]
-// CHECK:STDOUT:   %T.patt.loc19_23.2: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc19_23.2 (constants.%T.patt)]
-// CHECK:STDOUT:   %GenericInterface.type.loc19_54.2: type = facet_type <@GenericInterface, @GenericInterface(%T.loc19_23.2)> [symbolic = %GenericInterface.type.loc19_54.2 (constants.%GenericInterface.type.3fe)]
-// CHECK:STDOUT:   %require_complete: <witness> = require_complete_type @impl.%GenericInterface.type.loc19_54.2 (%GenericInterface.type.3fe) [symbolic = %require_complete (constants.%require_complete.70f)]
-// CHECK:STDOUT:   %impl_witness: <witness> = impl_witness (%F.decl), @impl(%T.loc19_23.2) [symbolic = %impl_witness (constants.%impl_witness)]
+// CHECK:STDOUT: generic impl @impl(%T.loc20_23.1: type) {
+// CHECK:STDOUT:   %T.loc20_23.2: type = bind_symbolic_name T, 0 [symbolic = %T.loc20_23.2 (constants.%T)]
+// CHECK:STDOUT:   %T.patt.loc20_23.2: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc20_23.2 (constants.%T.patt)]
+// CHECK:STDOUT:   %GenericInterface.type.loc20_54.2: type = facet_type <@GenericInterface, @GenericInterface(%T.loc20_23.2)> [symbolic = %GenericInterface.type.loc20_54.2 (constants.%GenericInterface.type.3fe)]
+// CHECK:STDOUT:   %require_complete: <witness> = require_complete_type @impl.%GenericInterface.type.loc20_54.2 (%GenericInterface.type.3fe) [symbolic = %require_complete (constants.%require_complete.70f)]
+// CHECK:STDOUT:   %impl_witness: <witness> = impl_witness (%F.decl), @impl(%T.loc20_23.2) [symbolic = %impl_witness (constants.%impl_witness)]
 // CHECK:STDOUT:
 // CHECK:STDOUT: !definition:
-// CHECK:STDOUT:   %F.type: type = fn_type @F.2, @impl(%T.loc19_23.2) [symbolic = %F.type (constants.%F.type.2cb)]
+// CHECK:STDOUT:   %F.type: type = fn_type @F.2, @impl(%T.loc20_23.2) [symbolic = %F.type (constants.%F.type.2cb)]
 // CHECK:STDOUT:   %F: @impl.%F.type (%F.type.2cb) = struct_value () [symbolic = %F (constants.%F.4b1)]
 // CHECK:STDOUT:
-// CHECK:STDOUT:   impl: %Self.ref as %GenericInterface.type.loc19_54.1 {
+// CHECK:STDOUT:   impl: %Self.ref as %GenericInterface.type.loc20_54.1 {
 // CHECK:STDOUT:     %F.decl: @impl.%F.type (%F.type.2cb) = fn_decl @F.2 [symbolic = @impl.%F (constants.%F.4b1)] {
 // CHECK:STDOUT:       %x.patt: @F.2.%T (%T) = binding_pattern x
 // CHECK:STDOUT:       %x.param_patt: @F.2.%T (%T) = value_param_pattern %x.patt, runtime_param0
 // CHECK:STDOUT:     } {
 // CHECK:STDOUT:       %x.param: @F.2.%T (%T) = value_param runtime_param0
-// CHECK:STDOUT:       %T.ref: type = name_ref T, @impl.%T.loc19_23.1 [symbolic = %T (constants.%T)]
+// CHECK:STDOUT:       %T.ref: type = name_ref T, @impl.%T.loc20_23.1 [symbolic = %T (constants.%T)]
 // CHECK:STDOUT:       %x: @F.2.%T (%T) = bind_name x, %x.param
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:
@@ -129,18 +130,18 @@ class C {
 // CHECK:STDOUT:
 // CHECK:STDOUT: class @C {
 // CHECK:STDOUT:   impl_decl @impl [template] {
-// CHECK:STDOUT:     %T.patt.loc19_23.1: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc19_23.2 (constants.%T.patt)]
-// CHECK:STDOUT:     %T.param_patt: type = value_param_pattern %T.patt.loc19_23.1, runtime_param<invalid> [symbolic = %T.patt.loc19_23.2 (constants.%T.patt)]
+// CHECK:STDOUT:     %T.patt.loc20_23.1: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc20_23.2 (constants.%T.patt)]
+// CHECK:STDOUT:     %T.param_patt: type = value_param_pattern %T.patt.loc20_23.1, runtime_param<invalid> [symbolic = %T.patt.loc20_23.2 (constants.%T.patt)]
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %Self.ref: type = name_ref Self, constants.%C [template = constants.%C]
 // CHECK:STDOUT:     %GenericInterface.ref: %GenericInterface.type.c92 = name_ref GenericInterface, file.%GenericInterface.decl [template = constants.%GenericInterface.generic]
-// CHECK:STDOUT:     %T.ref: type = name_ref T, %T.loc19_23.1 [symbolic = %T.loc19_23.2 (constants.%T)]
-// CHECK:STDOUT:     %GenericInterface.type.loc19_54.1: type = facet_type <@GenericInterface, @GenericInterface(constants.%T)> [symbolic = %GenericInterface.type.loc19_54.2 (constants.%GenericInterface.type.3fe)]
+// CHECK:STDOUT:     %T.ref: type = name_ref T, %T.loc20_23.1 [symbolic = %T.loc20_23.2 (constants.%T)]
+// CHECK:STDOUT:     %GenericInterface.type.loc20_54.1: type = facet_type <@GenericInterface, @GenericInterface(constants.%T)> [symbolic = %GenericInterface.type.loc20_54.2 (constants.%GenericInterface.type.3fe)]
 // CHECK:STDOUT:     %T.param: type = value_param runtime_param<invalid>
-// CHECK:STDOUT:     %T.loc19_23.1: type = bind_symbolic_name T, 0, %T.param [symbolic = %T.loc19_23.2 (constants.%T)]
+// CHECK:STDOUT:     %T.loc20_23.1: type = bind_symbolic_name T, 0, %T.param [symbolic = %T.loc20_23.2 (constants.%T)]
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %impl_witness: <witness> = impl_witness (@impl.%F.decl), @impl(constants.%T) [symbolic = @impl.%impl_witness (constants.%impl_witness)]
-// CHECK:STDOUT:   %.loc19: type = specific_constant @impl.%GenericInterface.type.loc19_54.1, @impl(constants.%T) [symbolic = constants.%GenericInterface.type.3fe]
+// CHECK:STDOUT:   %.loc20: type = specific_constant @impl.%GenericInterface.type.loc20_54.1, @impl(constants.%T) [symbolic = constants.%GenericInterface.type.3fe]
 // CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [template = constants.%complete_type]
 // CHECK:STDOUT:   complete_type_witness = %complete_type
 // CHECK:STDOUT: }
@@ -151,7 +152,7 @@ class C {
 // CHECK:STDOUT:   fn(%x.param_patt: @F.1.%T (%T));
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: generic fn @F.2(@impl.%T.loc19_23.1: type) {
+// CHECK:STDOUT: generic fn @F.2(@impl.%T.loc20_23.1: type) {
 // CHECK:STDOUT:   %T: type = bind_symbolic_name T, 0 [symbolic = %T (constants.%T)]
 // CHECK:STDOUT:
 // CHECK:STDOUT: !definition:
@@ -183,9 +184,9 @@ class C {
 // CHECK:STDOUT: specific @GenericInterface(%T.loc11_28.2) {}
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @impl(constants.%T) {
-// CHECK:STDOUT:   %T.loc19_23.2 => constants.%T
-// CHECK:STDOUT:   %T.patt.loc19_23.2 => constants.%T
-// CHECK:STDOUT:   %GenericInterface.type.loc19_54.2 => constants.%GenericInterface.type.3fe
+// CHECK:STDOUT:   %T.loc20_23.2 => constants.%T
+// CHECK:STDOUT:   %T.patt.loc20_23.2 => constants.%T
+// CHECK:STDOUT:   %GenericInterface.type.loc20_54.2 => constants.%GenericInterface.type.3fe
 // CHECK:STDOUT:   %require_complete => constants.%require_complete.70f
 // CHECK:STDOUT:   %impl_witness => constants.%impl_witness
 // CHECK:STDOUT:
@@ -194,9 +195,9 @@ class C {
 // CHECK:STDOUT:   %F => constants.%F.4b1
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: specific @GenericInterface(@impl.%T.loc19_23.2) {}
+// CHECK:STDOUT: specific @GenericInterface(@impl.%T.loc20_23.2) {}
 // CHECK:STDOUT:
-// CHECK:STDOUT: specific @impl(%T.loc19_23.2) {}
+// CHECK:STDOUT: specific @impl(%T.loc20_23.2) {}
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @F.2(constants.%T) {
 // CHECK:STDOUT:   %T => constants.%T
diff --git a/toolchain/check/testdata/impl/fail_extend_impl_scope.carbon b/toolchain/check/testdata/impl/fail_extend_impl_scope.carbon
index 5d99b3ad1996..4c6730119b7c 100644
--- a/toolchain/check/testdata/impl/fail_extend_impl_scope.carbon
+++ b/toolchain/check/testdata/impl/fail_extend_impl_scope.carbon
@@ -10,9 +10,10 @@
 
 interface I {}
 
-// CHECK:STDERR: fail_extend_impl_scope.carbon:[[@LINE+3]]:1: error: `extend impl` can only be used in a class [ExtendImplOutsideClass]
+// CHECK:STDERR: fail_extend_impl_scope.carbon:[[@LINE+4]]:1: error: `extend impl` can only be used in a class [ExtendImplOutsideClass]
 // CHECK:STDERR: extend impl i32 as I {}
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 extend impl i32 as I {}
 
 // CHECK:STDOUT: --- fail_extend_impl_scope.carbon
diff --git a/toolchain/check/testdata/impl/fail_extend_impl_type_as.carbon b/toolchain/check/testdata/impl/fail_extend_impl_type_as.carbon
index 1b85da753f3a..433e5c3d9891 100644
--- a/toolchain/check/testdata/impl/fail_extend_impl_type_as.carbon
+++ b/toolchain/check/testdata/impl/fail_extend_impl_type_as.carbon
@@ -30,16 +30,17 @@ class D {
 }
 
 class E {
-  // CHECK:STDERR: fail_extend_impl_type_as.carbon:[[@LINE+10]]:3: error: cannot `extend` an `impl` with an explicit self type [ExtendImplSelfAs]
+  // CHECK:STDERR: fail_extend_impl_type_as.carbon:[[@LINE+11]]:3: error: cannot `extend` an `impl` with an explicit self type [ExtendImplSelfAs]
   // CHECK:STDERR:   extend impl Self as I {}
   // CHECK:STDERR:   ^~~~~~
-  // CHECK:STDERR: fail_extend_impl_type_as.carbon:[[@LINE+7]]:15: note: remove the explicit `Self` type here [ExtendImplSelfAsDefault]
+  // CHECK:STDERR: fail_extend_impl_type_as.carbon:[[@LINE+8]]:15: note: remove the explicit `Self` type here [ExtendImplSelfAsDefault]
   // CHECK:STDERR:   extend impl Self as I {}
   // CHECK:STDERR:               ^~~~
   // CHECK:STDERR:
   // CHECK:STDERR: fail_extend_impl_type_as.carbon:[[@LINE-11]]:3: error: impl declared but not defined [ImplMissingDefinition]
   // CHECK:STDERR:   extend impl D as I;
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   extend impl Self as I {}
 }
 
diff --git a/toolchain/check/testdata/impl/fail_extend_non_interface.carbon b/toolchain/check/testdata/impl/fail_extend_non_interface.carbon
index 9e10b79eecf5..054e9a148f8e 100644
--- a/toolchain/check/testdata/impl/fail_extend_non_interface.carbon
+++ b/toolchain/check/testdata/impl/fail_extend_non_interface.carbon
@@ -9,17 +9,18 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/fail_extend_non_interface.carbon
 
 class C {
-  // CHECK:STDERR: fail_extend_non_interface.carbon:[[@LINE+11]]:3: error: impl as non-facet type `i32` [ImplAsNonFacetType]
+  // CHECK:STDERR: fail_extend_non_interface.carbon:[[@LINE+12]]:3: error: impl as non-facet type `i32` [ImplAsNonFacetType]
   // CHECK:STDERR:   extend impl as i32;
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_extend_non_interface.carbon:[[@LINE+7]]:3: error: semantics TODO: `extending non-facet-type constraint` [SemanticsTodo]
+  // CHECK:STDERR: fail_extend_non_interface.carbon:[[@LINE+8]]:3: error: semantics TODO: `extending non-facet-type constraint` [SemanticsTodo]
   // CHECK:STDERR:   extend impl as i32;
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_extend_non_interface.carbon:[[@LINE+3]]:3: error: impl declared but not defined [ImplMissingDefinition]
+  // CHECK:STDERR: fail_extend_non_interface.carbon:[[@LINE+4]]:3: error: impl declared but not defined [ImplMissingDefinition]
   // CHECK:STDERR:   extend impl as i32;
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   extend impl as i32;
 }
 
diff --git a/toolchain/check/testdata/impl/fail_extend_partially_defined_interface.carbon b/toolchain/check/testdata/impl/fail_extend_partially_defined_interface.carbon
index 9d41c78d65e0..a2a3c2bf579f 100644
--- a/toolchain/check/testdata/impl/fail_extend_partially_defined_interface.carbon
+++ b/toolchain/check/testdata/impl/fail_extend_partially_defined_interface.carbon
@@ -10,16 +10,17 @@
 
 interface I {
   class C {
-    // CHECK:STDERR: fail_extend_partially_defined_interface.carbon:[[@LINE+10]]:5: error: implementation of undefined interface I [ImplOfUndefinedInterface]
+    // CHECK:STDERR: fail_extend_partially_defined_interface.carbon:[[@LINE+11]]:5: error: implementation of undefined interface I [ImplOfUndefinedInterface]
     // CHECK:STDERR:     extend impl as I;
     // CHECK:STDERR:     ^~~~~~~~~~~~~~~~~
     // CHECK:STDERR: fail_extend_partially_defined_interface.carbon:[[@LINE-5]]:1: note: interface is currently being defined [InterfaceUndefinedWithinDefinition]
     // CHECK:STDERR: interface I {
     // CHECK:STDERR: ^~~~~~~~~~~~~
     // CHECK:STDERR:
-    // CHECK:STDERR: fail_extend_partially_defined_interface.carbon:[[@LINE+3]]:5: error: impl declared but not defined [ImplMissingDefinition]
+    // CHECK:STDERR: fail_extend_partially_defined_interface.carbon:[[@LINE+4]]:5: error: impl declared but not defined [ImplMissingDefinition]
     // CHECK:STDERR:     extend impl as I;
     // CHECK:STDERR:     ^~~~~~~~~~~~~~~~~
+    // CHECK:STDERR:
     extend impl as I;
   }
 }
@@ -76,7 +77,7 @@ interface I {
 // CHECK:STDOUT:       %Self.ref: type = name_ref Self, constants.%C.6b4 [symbolic = %C (constants.%C.6b4)]
 // CHECK:STDOUT:       %I.ref: type = name_ref I, file.%I.decl [template = constants.%I.type]
 // CHECK:STDOUT:     }
-// CHECK:STDOUT:     %.loc23: type = specific_constant @impl.%I.ref, @impl(constants.%Self) [template = constants.%I.type]
+// CHECK:STDOUT:     %.loc24: type = specific_constant @impl.%I.ref, @impl(constants.%Self) [template = constants.%I.type]
 // CHECK:STDOUT:     %complete_type: <witness> = complete_type_witness %empty_struct_type [template = constants.%complete_type]
 // CHECK:STDOUT:     complete_type_witness = %complete_type
 // CHECK:STDOUT:   }
diff --git a/toolchain/check/testdata/impl/fail_extend_undefined_interface.carbon b/toolchain/check/testdata/impl/fail_extend_undefined_interface.carbon
index 6ab7f3735594..01461cbb3cae 100644
--- a/toolchain/check/testdata/impl/fail_extend_undefined_interface.carbon
+++ b/toolchain/check/testdata/impl/fail_extend_undefined_interface.carbon
@@ -33,7 +33,7 @@ fn F(c: C) {
   // CHECK:STDERR:                  ^
   // CHECK:STDERR:
   C.F();
-  // CHECK:STDERR: fail_extend_undefined_interface.carbon:[[@LINE+13]]:3: error: member access into undefined interface `I` [QualifiedExprInUndefinedInterfaceScope]
+  // CHECK:STDERR: fail_extend_undefined_interface.carbon:[[@LINE+14]]:3: error: member access into undefined interface `I` [QualifiedExprInUndefinedInterfaceScope]
   // CHECK:STDERR:   c.F();
   // CHECK:STDERR:   ^~~
   // CHECK:STDERR: fail_extend_undefined_interface.carbon:[[@LINE-28]]:1: note: interface was forward declared here [InterfaceForwardDeclaredHere]
@@ -46,6 +46,7 @@ fn F(c: C) {
   // CHECK:STDERR: fail_extend_undefined_interface.carbon:[[@LINE-25]]:3: error: impl declared but not defined [ImplMissingDefinition]
   // CHECK:STDERR:   extend impl as I;
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   c.F();
 }
 
@@ -105,7 +106,7 @@ fn F(c: C) {
 // CHECK:STDOUT:   %C.ref.loc35: type = name_ref C, file.%C.decl [template = constants.%C]
 // CHECK:STDOUT:   %F.ref.loc35: <error> = name_ref F, <error> [template = <error>]
 // CHECK:STDOUT:   %c.ref: %C = name_ref c, %c
-// CHECK:STDOUT:   %F.ref.loc49: <error> = name_ref F, <error> [template = <error>]
+// CHECK:STDOUT:   %F.ref.loc50: <error> = name_ref F, <error> [template = <error>]
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/impl/fail_impl_as_scope.carbon b/toolchain/check/testdata/impl/fail_impl_as_scope.carbon
index 95e0ee7752f9..4818a78b1c7c 100644
--- a/toolchain/check/testdata/impl/fail_impl_as_scope.carbon
+++ b/toolchain/check/testdata/impl/fail_impl_as_scope.carbon
@@ -33,9 +33,10 @@ interface Simple {
 }
 
 fn Function() {
-  // CHECK:STDERR: fail_function.carbon:[[@LINE+3]]:8: error: `impl as` can only be used in a class [ImplAsOutsideClass]
+  // CHECK:STDERR: fail_function.carbon:[[@LINE+4]]:8: error: `impl as` can only be used in a class [ImplAsOutsideClass]
   // CHECK:STDERR:   impl as Simple {
   // CHECK:STDERR:        ^~
+  // CHECK:STDERR:
   impl as Simple {
     fn F() {}
   }
diff --git a/toolchain/check/testdata/impl/fail_impl_bad_assoc_fn.carbon b/toolchain/check/testdata/impl/fail_impl_bad_assoc_fn.carbon
index e44a6b50eaa5..8c238d044fc4 100644
--- a/toolchain/check/testdata/impl/fail_impl_bad_assoc_fn.carbon
+++ b/toolchain/check/testdata/impl/fail_impl_bad_assoc_fn.carbon
@@ -203,12 +203,13 @@ class SelfNestedBadParam {
 
 class SelfNestedBadReturnType {
   impl as SelfNested {
-    // CHECK:STDERR: fail_impl_bad_assoc_fn.carbon:[[@LINE+6]]:5: error: function redeclaration differs because return type is `[SelfNestedBadParam; 4]` [FunctionRedeclReturnTypeDiffers]
+    // CHECK:STDERR: fail_impl_bad_assoc_fn.carbon:[[@LINE+7]]:5: error: function redeclaration differs because return type is `[SelfNestedBadParam; 4]` [FunctionRedeclReturnTypeDiffers]
     // CHECK:STDERR:     fn F(x: (SelfNestedBadReturnType*, {.x: SelfNestedBadReturnType, .y: i32})) -> [SelfNestedBadParam; 4];
     // CHECK:STDERR:     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     // CHECK:STDERR: fail_impl_bad_assoc_fn.carbon:[[@LINE-21]]:3: note: previously declared with return type `[SelfNestedBadReturnType; 4]` [FunctionRedeclReturnTypePrevious]
     // CHECK:STDERR:   fn F(x: (Self*, {.x: Self, .y: i32})) -> [Self; 4];
     // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+    // CHECK:STDERR:
     fn F(x: (SelfNestedBadReturnType*, {.x: SelfNestedBadReturnType, .y: i32})) -> [SelfNestedBadParam; 4];
   }
 }
@@ -797,15 +798,15 @@ class SelfNestedBadReturnType {
 // CHECK:STDOUT:     %int_4: Core.IntLiteral = int_value 4 [template = constants.%int_4]
 // CHECK:STDOUT:     %array_type: type = array_type %int_4, %SelfNestedBadParam [template = constants.%array_type.a41]
 // CHECK:STDOUT:     %x.param: %tuple.type.eb9 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc212_78.1: type = splice_block %.loc212_78.3 [template = constants.%tuple.type.eb9] {
-// CHECK:STDOUT:       %SelfNestedBadReturnType.ref.loc212_14: type = name_ref SelfNestedBadReturnType, file.%SelfNestedBadReturnType.decl [template = constants.%SelfNestedBadReturnType]
+// CHECK:STDOUT:     %.loc213_78.1: type = splice_block %.loc213_78.3 [template = constants.%tuple.type.eb9] {
+// CHECK:STDOUT:       %SelfNestedBadReturnType.ref.loc213_14: type = name_ref SelfNestedBadReturnType, file.%SelfNestedBadReturnType.decl [template = constants.%SelfNestedBadReturnType]
 // CHECK:STDOUT:       %ptr: type = ptr_type %SelfNestedBadReturnType [template = constants.%ptr.612]
-// CHECK:STDOUT:       %SelfNestedBadReturnType.ref.loc212_45: type = name_ref SelfNestedBadReturnType, file.%SelfNestedBadReturnType.decl [template = constants.%SelfNestedBadReturnType]
+// CHECK:STDOUT:       %SelfNestedBadReturnType.ref.loc213_45: type = name_ref SelfNestedBadReturnType, file.%SelfNestedBadReturnType.decl [template = constants.%SelfNestedBadReturnType]
 // CHECK:STDOUT:       %int_32: Core.IntLiteral = int_value 32 [template = constants.%int_32]
 // CHECK:STDOUT:       %i32: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
 // CHECK:STDOUT:       %struct_type.x.y: type = struct_type {.x: %SelfNestedBadReturnType, .y: %i32} [template = constants.%struct_type.x.y.ac5]
-// CHECK:STDOUT:       %.loc212_78.2: %tuple.type.24b = tuple_literal (%ptr, %struct_type.x.y)
-// CHECK:STDOUT:       %.loc212_78.3: type = converted %.loc212_78.2, constants.%tuple.type.eb9 [template = constants.%tuple.type.eb9]
+// CHECK:STDOUT:       %.loc213_78.2: %tuple.type.24b = tuple_literal (%ptr, %struct_type.x.y)
+// CHECK:STDOUT:       %.loc213_78.3: type = converted %.loc213_78.2, constants.%tuple.type.eb9 [template = constants.%tuple.type.eb9]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %x: %tuple.type.eb9 = bind_name x, %x.param
 // CHECK:STDOUT:     %return.param: ref %array_type.a41 = out_param runtime_param1
diff --git a/toolchain/check/testdata/impl/fail_impl_bad_interface.carbon b/toolchain/check/testdata/impl/fail_impl_bad_interface.carbon
index 3ea235eb825d..4dd3db7fa213 100644
--- a/toolchain/check/testdata/impl/fail_impl_bad_interface.carbon
+++ b/toolchain/check/testdata/impl/fail_impl_bad_interface.carbon
@@ -38,9 +38,10 @@ library "[[@TEST_NAME]]";
 // Note: This code is not expected to pass checking, even once the TODO is
 // addressed.
 
-// CHECK:STDERR: fail_impl_as_type_where.carbon:[[@LINE+3]]:1: error: semantics TODO: `impl as not 1 interface` [SemanticsTodo]
+// CHECK:STDERR: fail_impl_as_type_where.carbon:[[@LINE+4]]:1: error: semantics TODO: `impl as not 1 interface` [SemanticsTodo]
 // CHECK:STDERR: impl f64 as type where .Self impls type {}
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 impl f64 as type where .Self impls type {}
 
 // CHECK:STDOUT: --- fail_impl_as_false.carbon
@@ -136,17 +137,17 @@ impl f64 as type where .Self impls type {}
 // CHECK:STDOUT:   impl_decl @impl [template] {} {
 // CHECK:STDOUT:     %int_64: Core.IntLiteral = int_value 64 [template = constants.%int_64]
 // CHECK:STDOUT:     %float.make_type: init type = call constants.%Float(%int_64) [template = f64]
-// CHECK:STDOUT:     %.loc10_6.1: type = value_of_initializer %float.make_type [template = f64]
-// CHECK:STDOUT:     %.loc10_6.2: type = converted %float.make_type, %.loc10_6.1 [template = f64]
+// CHECK:STDOUT:     %.loc11_6.1: type = value_of_initializer %float.make_type [template = f64]
+// CHECK:STDOUT:     %.loc11_6.2: type = converted %float.make_type, %.loc11_6.1 [template = f64]
 // CHECK:STDOUT:     %.Self: type = bind_symbolic_name .Self [symbolic = constants.%.Self]
 // CHECK:STDOUT:     %.Self.ref: type = name_ref .Self, %.Self [symbolic = constants.%.Self]
-// CHECK:STDOUT:     %.loc10_18: type = where_expr %.Self [template = constants.%type_where] {
+// CHECK:STDOUT:     %.loc11_18: type = where_expr %.Self [template = constants.%type_where] {
 // CHECK:STDOUT:       requirement_impls %.Self.ref, type
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl: %.loc10_6.2 as %.loc10_18 {
+// CHECK:STDOUT: impl @impl: %.loc11_6.2 as %.loc11_18 {
 // CHECK:STDOUT: !members:
 // CHECK:STDOUT:   witness = <error>
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/impl/fail_redefinition.carbon b/toolchain/check/testdata/impl/fail_redefinition.carbon
index 1d07be8143e9..efe53fda0840 100644
--- a/toolchain/check/testdata/impl/fail_redefinition.carbon
+++ b/toolchain/check/testdata/impl/fail_redefinition.carbon
@@ -12,12 +12,13 @@ interface I {}
 
 impl i32 as I {}
 
-// CHECK:STDERR: fail_redefinition.carbon:[[@LINE+6]]:1: error: redefinition of `impl i32 as I` [ImplRedefinition]
+// CHECK:STDERR: fail_redefinition.carbon:[[@LINE+7]]:1: error: redefinition of `impl i32 as I` [ImplRedefinition]
 // CHECK:STDERR: impl i32 as I {}
 // CHECK:STDERR: ^~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_redefinition.carbon:[[@LINE-5]]:1: note: previous definition was here [ImplPreviousDefinition]
 // CHECK:STDERR: impl i32 as I {}
 // CHECK:STDERR: ^~~~~~~~~~~~~~~
+// CHECK:STDERR:
 impl i32 as I {}
 
 // CHECK:STDOUT: --- fail_redefinition.carbon
@@ -56,7 +57,7 @@ impl i32 as I {}
 // CHECK:STDOUT:     %i32: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
 // CHECK:STDOUT:     %I.ref: type = name_ref I, file.%I.decl [template = constants.%I.type]
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %impl_witness.loc21: <witness> = impl_witness () [template = constants.%impl_witness]
+// CHECK:STDOUT:   %impl_witness.loc22: <witness> = impl_witness () [template = constants.%impl_witness]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: interface @I {
@@ -74,6 +75,6 @@ impl i32 as I {}
 // CHECK:STDOUT:
 // CHECK:STDOUT: impl @impl.2: %i32 as %I.ref {
 // CHECK:STDOUT: !members:
-// CHECK:STDOUT:   witness = file.%impl_witness.loc21
+// CHECK:STDOUT:   witness = file.%impl_witness.loc22
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/impl/fail_self_type_mismatch.carbon b/toolchain/check/testdata/impl/fail_self_type_mismatch.carbon
index 056f1e412ec3..691f6ee3c9ab 100644
--- a/toolchain/check/testdata/impl/fail_self_type_mismatch.carbon
+++ b/toolchain/check/testdata/impl/fail_self_type_mismatch.carbon
@@ -15,12 +15,13 @@ interface I {
 }
 
 impl i32 as I {
-  // CHECK:STDERR: fail_self_type_mismatch.carbon:[[@LINE+6]]:8: error: type `C(i32)` of parameter 1 in redeclaration differs from previous parameter type `C(i32 as I)` [RedeclParamDiffersType]
+  // CHECK:STDERR: fail_self_type_mismatch.carbon:[[@LINE+7]]:8: error: type `C(i32)` of parameter 1 in redeclaration differs from previous parameter type `C(i32 as I)` [RedeclParamDiffersType]
   // CHECK:STDERR:   fn F(c: C(i32));
   // CHECK:STDERR:        ^~~~~~~~~
   // CHECK:STDERR: fail_self_type_mismatch.carbon:[[@LINE-7]]:8: note: previous declaration's corresponding parameter here [RedeclParamPrevious]
   // CHECK:STDERR:   fn F(c: C(Self));
   // CHECK:STDERR:        ^~~~~~~~~~
+  // CHECK:STDERR:
   fn F(c: C(i32));
 }
 
@@ -116,7 +117,7 @@ impl i32 as I {
 // CHECK:STDOUT:     %c.param_patt: %C.6fb = value_param_pattern %c.patt, runtime_param0
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %c.param: %C.6fb = value_param runtime_param0
-// CHECK:STDOUT:     %.loc24: type = splice_block %C [template = constants.%C.6fb] {
+// CHECK:STDOUT:     %.loc25: type = splice_block %C [template = constants.%C.6fb] {
 // CHECK:STDOUT:       %C.ref: %C.type = name_ref C, file.%C.decl [template = constants.%C.generic]
 // CHECK:STDOUT:       %int_32: Core.IntLiteral = int_value 32 [template = constants.%int_32]
 // CHECK:STDOUT:       %i32: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
diff --git a/toolchain/check/testdata/impl/fail_todo_use_assoc_const.carbon b/toolchain/check/testdata/impl/fail_todo_use_assoc_const.carbon
index 3f91b06fd4be..55541d667732 100644
--- a/toolchain/check/testdata/impl/fail_todo_use_assoc_const.carbon
+++ b/toolchain/check/testdata/impl/fail_todo_use_assoc_const.carbon
@@ -69,12 +69,13 @@ library "[[@TEST_NAME]]";
 
 interface I {
   let N:! i32;
-  // CHECK:STDERR: fail_todo_associated_int_in_array.carbon:[[@LINE+6]]:32: error: cannot implicitly convert from `<associated i32 in I>` to `Core.IntLiteral` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_todo_associated_int_in_array.carbon:[[@LINE+7]]:32: error: cannot implicitly convert from `<associated i32 in I>` to `Core.IntLiteral` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   fn F[self: Self]() -> [bool; N];
   // CHECK:STDERR:                                ^
-  // CHECK:STDERR: fail_todo_associated_int_in_array.carbon:[[@LINE+3]]:32: note: type `<associated i32 in I>` does not implement interface `Core.ImplicitAs(Core.IntLiteral)` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR: fail_todo_associated_int_in_array.carbon:[[@LINE+4]]:32: note: type `<associated i32 in I>` does not implement interface `Core.ImplicitAs(Core.IntLiteral)` [MissingImplInMemberAccessNote]
   // CHECK:STDERR:   fn F[self: Self]() -> [bool; N];
   // CHECK:STDERR:                                ^
+  // CHECK:STDERR:
   fn F[self: Self]() -> [bool; N];
 }
 
@@ -477,23 +478,23 @@ impl () as I where .N = 2 {
 // CHECK:STDOUT:   %Core.import = import Core
 // CHECK:STDOUT:   %I.decl: type = interface_decl @I [template = constants.%I.type] {} {}
 // CHECK:STDOUT:   impl_decl @impl.44 [template] {} {
-// CHECK:STDOUT:     %.loc14_7.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc14_7.2: type = converted %.loc14_7.1, constants.%empty_tuple.type [template = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %.loc15_7.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc15_7.2: type = converted %.loc15_7.1, constants.%empty_tuple.type [template = constants.%empty_tuple.type]
 // CHECK:STDOUT:     %I.ref: type = name_ref I, file.%I.decl [template = constants.%I.type]
 // CHECK:STDOUT:     %.Self: %I.type = bind_symbolic_name .Self [symbolic = constants.%.Self]
 // CHECK:STDOUT:     %.Self.ref: %I.type = name_ref .Self, %.Self [symbolic = constants.%.Self]
 // CHECK:STDOUT:     %N.ref: %assoc_type = name_ref N, @I.%assoc0 [template = constants.%assoc0.9f1]
 // CHECK:STDOUT:     %.Self.as_wit: <witness> = facet_access_witness %.Self.ref [symbolic = constants.%.Self.as_wit]
-// CHECK:STDOUT:     %impl.elem0.loc14_20: %i32 = impl_witness_access %.Self.as_wit, element0 [symbolic = constants.%impl.elem0]
+// CHECK:STDOUT:     %impl.elem0.loc15_20: %i32 = impl_witness_access %.Self.as_wit, element0 [symbolic = constants.%impl.elem0]
 // CHECK:STDOUT:     %int_2: Core.IntLiteral = int_value 2 [template = constants.%int_2.ecc]
-// CHECK:STDOUT:     %impl.elem0.loc14_25: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
-// CHECK:STDOUT:     %Convert.bound: <bound method> = bound_method %int_2, %impl.elem0.loc14_25 [template = constants.%Convert.bound]
+// CHECK:STDOUT:     %impl.elem0.loc15_25: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
+// CHECK:STDOUT:     %Convert.bound: <bound method> = bound_method %int_2, %impl.elem0.loc15_25 [template = constants.%Convert.bound]
 // CHECK:STDOUT:     %Convert.specific_fn: <specific function> = specific_function %Convert.bound, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn]
 // CHECK:STDOUT:     %int.convert_checked: init %i32 = call %Convert.specific_fn(%int_2) [template = constants.%int_2.ef8]
-// CHECK:STDOUT:     %.loc14_25.1: %i32 = value_of_initializer %int.convert_checked [template = constants.%int_2.ef8]
-// CHECK:STDOUT:     %.loc14_25.2: %i32 = converted %int_2, %.loc14_25.1 [template = constants.%int_2.ef8]
-// CHECK:STDOUT:     %.loc14_14: type = where_expr %.Self [template = constants.%I_where.type] {
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc14_20, %.loc14_25.2
+// CHECK:STDOUT:     %.loc15_25.1: %i32 = value_of_initializer %int.convert_checked [template = constants.%int_2.ef8]
+// CHECK:STDOUT:     %.loc15_25.2: %i32 = converted %int_2, %.loc15_25.1 [template = constants.%int_2.ef8]
+// CHECK:STDOUT:     %.loc15_14: type = where_expr %.Self [template = constants.%I_where.type] {
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc15_20, %.loc15_25.2
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %impl_witness: <witness> = impl_witness (constants.%int_2.ef8, <error>) [template = constants.%impl_witness.2c9]
@@ -504,24 +505,24 @@ impl () as I where .N = 2 {
 // CHECK:STDOUT:   %N: %i32 = assoc_const_decl N [template]
 // CHECK:STDOUT:   %assoc0: %assoc_type = assoc_entity element0, %N [template = constants.%assoc0.9f1]
 // CHECK:STDOUT:   %F.decl: %F.type.cf0 = fn_decl @F.1 [template = constants.%F.bc6] {
-// CHECK:STDOUT:     %self.patt: @F.1.%Self.as_type.loc11_14.1 (%Self.as_type.b70) = binding_pattern self
-// CHECK:STDOUT:     %self.param_patt: @F.1.%Self.as_type.loc11_14.1 (%Self.as_type.b70) = value_param_pattern %self.patt, runtime_param0
+// CHECK:STDOUT:     %self.patt: @F.1.%Self.as_type.loc12_14.1 (%Self.as_type.b70) = binding_pattern self
+// CHECK:STDOUT:     %self.param_patt: @F.1.%Self.as_type.loc12_14.1 (%Self.as_type.b70) = value_param_pattern %self.patt, runtime_param0
 // CHECK:STDOUT:     %return.patt: <error> = return_slot_pattern
 // CHECK:STDOUT:     %return.param_patt: <error> = out_param_pattern %return.patt, runtime_param1
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %bool.make_type: init type = call constants.%Bool() [template = bool]
 // CHECK:STDOUT:     %N.ref: %assoc_type = name_ref N, @I.%assoc0 [template = constants.%assoc0.9f1]
-// CHECK:STDOUT:     %.loc11_26.1: type = value_of_initializer %bool.make_type [template = bool]
-// CHECK:STDOUT:     %.loc11_26.2: type = converted %bool.make_type, %.loc11_26.1 [template = bool]
-// CHECK:STDOUT:     %.loc11_32: Core.IntLiteral = converted %N.ref, <error> [template = <error>]
+// CHECK:STDOUT:     %.loc12_26.1: type = value_of_initializer %bool.make_type [template = bool]
+// CHECK:STDOUT:     %.loc12_26.2: type = converted %bool.make_type, %.loc12_26.1 [template = bool]
+// CHECK:STDOUT:     %.loc12_32: Core.IntLiteral = converted %N.ref, <error> [template = <error>]
 // CHECK:STDOUT:     %array_type: type = array_type <error>, bool [template = <error>]
-// CHECK:STDOUT:     %self.param: @F.1.%Self.as_type.loc11_14.1 (%Self.as_type.b70) = value_param runtime_param0
-// CHECK:STDOUT:     %.loc11_14.1: type = splice_block %.loc11_14.2 [symbolic = %Self.as_type.loc11_14.1 (constants.%Self.as_type.b70)] {
+// CHECK:STDOUT:     %self.param: @F.1.%Self.as_type.loc12_14.1 (%Self.as_type.b70) = value_param runtime_param0
+// CHECK:STDOUT:     %.loc12_14.1: type = splice_block %.loc12_14.2 [symbolic = %Self.as_type.loc12_14.1 (constants.%Self.as_type.b70)] {
 // CHECK:STDOUT:       %Self.ref: %I.type = name_ref Self, @I.%Self [symbolic = %Self (constants.%Self.826)]
-// CHECK:STDOUT:       %Self.as_type.loc11_14.2: type = facet_access_type %Self.ref [symbolic = %Self.as_type.loc11_14.1 (constants.%Self.as_type.b70)]
-// CHECK:STDOUT:       %.loc11_14.2: type = converted %Self.ref, %Self.as_type.loc11_14.2 [symbolic = %Self.as_type.loc11_14.1 (constants.%Self.as_type.b70)]
+// CHECK:STDOUT:       %Self.as_type.loc12_14.2: type = facet_access_type %Self.ref [symbolic = %Self.as_type.loc12_14.1 (constants.%Self.as_type.b70)]
+// CHECK:STDOUT:       %.loc12_14.2: type = converted %Self.ref, %Self.as_type.loc12_14.2 [symbolic = %Self.as_type.loc12_14.1 (constants.%Self.as_type.b70)]
 // CHECK:STDOUT:     }
-// CHECK:STDOUT:     %self: @F.1.%Self.as_type.loc11_14.1 (%Self.as_type.b70) = bind_name self, %self.param
+// CHECK:STDOUT:     %self: @F.1.%Self.as_type.loc12_14.1 (%Self.as_type.b70) = bind_name self, %self.param
 // CHECK:STDOUT:     %return.param: ref <error> = out_param runtime_param1
 // CHECK:STDOUT:     %return: ref <error> = return_slot %return.param
 // CHECK:STDOUT:   }
@@ -534,7 +535,7 @@ impl () as I where .N = 2 {
 // CHECK:STDOUT:   witness = (%N, %F.decl)
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl.44: %.loc14_7.2 as %.loc14_14 {
+// CHECK:STDOUT: impl @impl.44: %.loc15_7.2 as %.loc15_14 {
 // CHECK:STDOUT:   %F.decl: %F.type.9f6 = fn_decl @F.2 [template = constants.%F.572] {
 // CHECK:STDOUT:     %self.patt: %empty_tuple.type = binding_pattern self
 // CHECK:STDOUT:     %self.param_patt: %empty_tuple.type = value_param_pattern %self.patt, runtime_param0
@@ -543,11 +544,11 @@ impl () as I where .N = 2 {
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %bool.make_type: init type = call constants.%Bool() [template = bool]
 // CHECK:STDOUT:     %int_2: Core.IntLiteral = int_value 2 [template = constants.%int_2.ecc]
-// CHECK:STDOUT:     %.loc15_26.1: type = value_of_initializer %bool.make_type [template = bool]
-// CHECK:STDOUT:     %.loc15_26.2: type = converted %bool.make_type, %.loc15_26.1 [template = bool]
+// CHECK:STDOUT:     %.loc16_26.1: type = value_of_initializer %bool.make_type [template = bool]
+// CHECK:STDOUT:     %.loc16_26.2: type = converted %bool.make_type, %.loc16_26.1 [template = bool]
 // CHECK:STDOUT:     %array_type: type = array_type %int_2, bool [template = constants.%array_type]
 // CHECK:STDOUT:     %self.param: %empty_tuple.type = value_param runtime_param0
-// CHECK:STDOUT:     %Self.ref: type = name_ref Self, @impl.44.%.loc14_7.2 [template = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %Self.ref: type = name_ref Self, @impl.44.%.loc15_7.2 [template = constants.%empty_tuple.type]
 // CHECK:STDOUT:     %self: %empty_tuple.type = bind_name self, %self.param
 // CHECK:STDOUT:     %return.param: ref %array_type = out_param runtime_param1
 // CHECK:STDOUT:     %return: ref %array_type = return_slot %return.param
@@ -560,34 +561,34 @@ impl () as I where .N = 2 {
 // CHECK:STDOUT:
 // CHECK:STDOUT: generic fn @F.1(@I.%Self: %I.type) {
 // CHECK:STDOUT:   %Self: %I.type = bind_symbolic_name Self, 0 [symbolic = %Self (constants.%Self.826)]
-// CHECK:STDOUT:   %Self.as_type.loc11_14.1: type = facet_access_type %Self [symbolic = %Self.as_type.loc11_14.1 (constants.%Self.as_type.b70)]
+// CHECK:STDOUT:   %Self.as_type.loc12_14.1: type = facet_access_type %Self [symbolic = %Self.as_type.loc12_14.1 (constants.%Self.as_type.b70)]
 // CHECK:STDOUT:
-// CHECK:STDOUT:   fn[%self.param_patt: @F.1.%Self.as_type.loc11_14.1 (%Self.as_type.b70)]() -> <error>;
+// CHECK:STDOUT:   fn[%self.param_patt: @F.1.%Self.as_type.loc12_14.1 (%Self.as_type.b70)]() -> <error>;
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @F.2[%self.param_patt: %empty_tuple.type]() -> %return.param_patt: %array_type {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %true: bool = bool_literal true [template = constants.%true]
 // CHECK:STDOUT:   %false: bool = bool_literal false [template = constants.%false]
-// CHECK:STDOUT:   %.loc15_56.1: %tuple.type = tuple_literal (%true, %false)
+// CHECK:STDOUT:   %.loc16_56.1: %tuple.type = tuple_literal (%true, %false)
 // CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [template = constants.%int_0]
-// CHECK:STDOUT:   %.loc15_56.2: ref bool = array_index %return, %int_0
-// CHECK:STDOUT:   %.loc15_56.3: init bool = initialize_from %true to %.loc15_56.2 [template = constants.%true]
+// CHECK:STDOUT:   %.loc16_56.2: ref bool = array_index %return, %int_0
+// CHECK:STDOUT:   %.loc16_56.3: init bool = initialize_from %true to %.loc16_56.2 [template = constants.%true]
 // CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [template = constants.%int_1]
-// CHECK:STDOUT:   %.loc15_56.4: ref bool = array_index %return, %int_1
-// CHECK:STDOUT:   %.loc15_56.5: init bool = initialize_from %false to %.loc15_56.4 [template = constants.%false]
-// CHECK:STDOUT:   %.loc15_56.6: init %array_type = array_init (%.loc15_56.3, %.loc15_56.5) to %return [template = constants.%array]
-// CHECK:STDOUT:   %.loc15_57: init %array_type = converted %.loc15_56.1, %.loc15_56.6 [template = constants.%array]
-// CHECK:STDOUT:   return %.loc15_57 to %return
+// CHECK:STDOUT:   %.loc16_56.4: ref bool = array_index %return, %int_1
+// CHECK:STDOUT:   %.loc16_56.5: init bool = initialize_from %false to %.loc16_56.4 [template = constants.%false]
+// CHECK:STDOUT:   %.loc16_56.6: init %array_type = array_init (%.loc16_56.3, %.loc16_56.5) to %return [template = constants.%array]
+// CHECK:STDOUT:   %.loc16_57: init %array_type = converted %.loc16_56.1, %.loc16_56.6 [template = constants.%array]
+// CHECK:STDOUT:   return %.loc16_57 to %return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @F.1(constants.%Self.826) {
 // CHECK:STDOUT:   %Self => constants.%Self.826
-// CHECK:STDOUT:   %Self.as_type.loc11_14.1 => constants.%Self.as_type.b70
+// CHECK:STDOUT:   %Self.as_type.loc12_14.1 => constants.%Self.as_type.b70
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @F.1(constants.%I.facet) {
 // CHECK:STDOUT:   %Self => constants.%I.facet
-// CHECK:STDOUT:   %Self.as_type.loc11_14.1 => constants.%empty_tuple.type
+// CHECK:STDOUT:   %Self.as_type.loc12_14.1 => constants.%empty_tuple.type
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/impl/lookup/fail_alias_impl_not_found.carbon b/toolchain/check/testdata/impl/lookup/fail_alias_impl_not_found.carbon
index 9c6a8d06de2a..196807c82ac6 100644
--- a/toolchain/check/testdata/impl/lookup/fail_alias_impl_not_found.carbon
+++ b/toolchain/check/testdata/impl/lookup/fail_alias_impl_not_found.carbon
@@ -22,9 +22,10 @@ fn F(c: C) {
   // CHECK:STDERR:   ^~~
   // CHECK:STDERR:
   C.F();
-  // CHECK:STDERR: fail_alias_impl_not_found.carbon:[[@LINE+3]]:3: error: cannot access member of interface `I` in type `C` that does not implement that interface [MissingImplInMemberAccess]
+  // CHECK:STDERR: fail_alias_impl_not_found.carbon:[[@LINE+4]]:3: error: cannot access member of interface `I` in type `C` that does not implement that interface [MissingImplInMemberAccess]
   // CHECK:STDERR:   c.F();
   // CHECK:STDERR:   ^~~
+  // CHECK:STDERR:
   c.F();
 }
 
@@ -100,7 +101,7 @@ fn F(c: C) {
 // CHECK:STDOUT:   %C.ref.loc24: type = name_ref C, file.%C.decl [template = constants.%C]
 // CHECK:STDOUT:   %F.ref.loc24: %F.assoc_type = name_ref F, @C.%F [template = constants.%assoc0]
 // CHECK:STDOUT:   %c.ref: %C = name_ref c, %c
-// CHECK:STDOUT:   %F.ref.loc28: %F.assoc_type = name_ref F, @C.%F [template = constants.%assoc0]
+// CHECK:STDOUT:   %F.ref.loc29: %F.assoc_type = name_ref F, @C.%F [template = constants.%assoc0]
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/impl/lookup/fail_todo_undefined_impl.carbon b/toolchain/check/testdata/impl/lookup/fail_todo_undefined_impl.carbon
index 1a47326c99e8..0e2e31fdbc01 100644
--- a/toolchain/check/testdata/impl/lookup/fail_todo_undefined_impl.carbon
+++ b/toolchain/check/testdata/impl/lookup/fail_todo_undefined_impl.carbon
@@ -19,13 +19,14 @@ class C {
 }
 
 fn F() -> i32 {
-  // CHECK:STDERR: fail_todo_undefined_impl.carbon:[[@LINE+7]]:10: error: accessing member from impl before the end of its definition [ImplAccessMemberBeforeComplete]
+  // CHECK:STDERR: fail_todo_undefined_impl.carbon:[[@LINE+8]]:10: error: accessing member from impl before the end of its definition [ImplAccessMemberBeforeComplete]
   // CHECK:STDERR:   return C.F();
   // CHECK:STDERR:          ^~~
   // CHECK:STDERR:
   // CHECK:STDERR: fail_todo_undefined_impl.carbon:[[@LINE-8]]:3: error: impl declared but not defined [ImplMissingDefinition]
   // CHECK:STDERR:   extend impl as I;
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   return C.F();
 }
 
diff --git a/toolchain/check/testdata/impl/lookup/generic.carbon b/toolchain/check/testdata/impl/lookup/generic.carbon
index 2e268b16b8d2..5f2dbe5b3b56 100644
--- a/toolchain/check/testdata/impl/lookup/generic.carbon
+++ b/toolchain/check/testdata/impl/lookup/generic.carbon
@@ -115,9 +115,10 @@ class B {}
 fn G(x: A) {
   // TODO: It'd be nice to include a note here saying that deduction failed because
   // we deduced two different values for `T`.
-  // CHECK:STDERR: fail_inconsistent_deduction.carbon:[[@LINE+3]]:3: error: cannot access member of interface `HasF(B)` in type `A` that does not implement that interface [MissingImplInMemberAccess]
+  // CHECK:STDERR: fail_inconsistent_deduction.carbon:[[@LINE+4]]:3: error: cannot access member of interface `HasF(B)` in type `A` that does not implement that interface [MissingImplInMemberAccess]
   // CHECK:STDERR:   x.(HasF(B).F)();
   // CHECK:STDERR:   ^~~~~~~~~~~~~
+  // CHECK:STDERR:
   x.(HasF(B).F)();
 }
 
@@ -1183,8 +1184,8 @@ fn G(x: A) {
 // CHECK:STDOUT:   %HasF.ref: %HasF.type.fe3 = name_ref HasF, file.%HasF.decl [template = constants.%HasF.generic]
 // CHECK:STDOUT:   %B.ref: type = name_ref B, file.%B.decl [template = constants.%B]
 // CHECK:STDOUT:   %HasF.type: type = facet_type <@HasF, @HasF(constants.%B)> [template = constants.%HasF.type.2f5]
-// CHECK:STDOUT:   %.loc21: %F.assoc_type.00a = specific_constant @HasF.%assoc0.loc5_9.1, @HasF(constants.%B) [template = constants.%assoc0.c2a]
-// CHECK:STDOUT:   %F.ref: %F.assoc_type.00a = name_ref F, %.loc21 [template = constants.%assoc0.c2a]
+// CHECK:STDOUT:   %.loc22: %F.assoc_type.00a = specific_constant @HasF.%assoc0.loc5_9.1, @HasF(constants.%B) [template = constants.%assoc0.c2a]
+// CHECK:STDOUT:   %F.ref: %F.assoc_type.00a = name_ref F, %.loc22 [template = constants.%assoc0.c2a]
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/impl/lookup/no_prelude/import.carbon b/toolchain/check/testdata/impl/lookup/no_prelude/import.carbon
index f123a533b444..9d1dbb6285f2 100644
--- a/toolchain/check/testdata/impl/lookup/no_prelude/import.carbon
+++ b/toolchain/check/testdata/impl/lookup/no_prelude/import.carbon
@@ -183,9 +183,10 @@ import HasExtraInterfaces;
 fn Test(c: HasExtraInterfaces.C(type)) {
   // This triggers the import of a bunch more interfaces, which reallocates the
   // interface ValueStore. Ensure that doesn't result in a use-after-free crash.
-  // CHECK:STDERR: fail_use_has_extra_interfaces.carbon:[[@LINE+3]]:3: error: cannot access member of interface `HasExtraInterfaces.I` in type `HasExtraInterfaces.C(type)` that does not implement that interface [MissingImplInMemberAccess]
+  // CHECK:STDERR: fail_use_has_extra_interfaces.carbon:[[@LINE+4]]:3: error: cannot access member of interface `HasExtraInterfaces.I` in type `HasExtraInterfaces.C(type)` that does not implement that interface [MissingImplInMemberAccess]
   // CHECK:STDERR:   c.(HasExtraInterfaces.I.F)();
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   c.(HasExtraInterfaces.I.F)();
 }
 
@@ -1802,7 +1803,7 @@ fn Test(c: HasExtraInterfaces.C(type)) {
 // CHECK:STDOUT: fn @Test(%c.param_patt: %C.42e) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %c.ref: %C.42e = name_ref c, %c
-// CHECK:STDOUT:   %HasExtraInterfaces.ref.loc11: <namespace> = name_ref HasExtraInterfaces, imports.%HasExtraInterfaces [template = imports.%HasExtraInterfaces]
+// CHECK:STDOUT:   %HasExtraInterfaces.ref.loc12: <namespace> = name_ref HasExtraInterfaces, imports.%HasExtraInterfaces [template = imports.%HasExtraInterfaces]
 // CHECK:STDOUT:   %I.ref: type = name_ref I, imports.%import_ref.df2 [template = constants.%I.type]
 // CHECK:STDOUT:   %F.ref: %F.assoc_type = name_ref F, imports.%import_ref.fd4 [template = constants.%assoc0]
 // CHECK:STDOUT:   return
diff --git a/toolchain/check/testdata/impl/multiple_extend.carbon b/toolchain/check/testdata/impl/multiple_extend.carbon
index 58b7e82de6da..f3eb6832b26b 100644
--- a/toolchain/check/testdata/impl/multiple_extend.carbon
+++ b/toolchain/check/testdata/impl/multiple_extend.carbon
@@ -121,9 +121,10 @@ fn M(l: L) {
    // CHECK:STDERR:    ^~~
    // CHECK:STDERR:
    L.K();
-   // CHECK:STDERR: fail_ambiguous_impl_and_base.carbon:[[@LINE+3]]:4: error: ambiguous use of name `K` found in multiple extended scopes [NameAmbiguousDueToExtend]
+   // CHECK:STDERR: fail_ambiguous_impl_and_base.carbon:[[@LINE+4]]:4: error: ambiguous use of name `K` found in multiple extended scopes [NameAmbiguousDueToExtend]
    // CHECK:STDERR:    l.K();
    // CHECK:STDERR:    ^~~
+   // CHECK:STDERR:
    l.K();
 }
 
@@ -713,7 +714,7 @@ fn P(o: O) {
 // CHECK:STDOUT:   %L.ref.loc24: type = name_ref L, file.%L.decl [template = constants.%L]
 // CHECK:STDOUT:   %K.ref.loc24: <error> = name_ref K, <error> [template = <error>]
 // CHECK:STDOUT:   %l.ref: %L = name_ref l, %l
-// CHECK:STDOUT:   %K.ref.loc28: <error> = name_ref K, <error> [template = <error>]
+// CHECK:STDOUT:   %K.ref.loc29: <error> = name_ref K, <error> [template = <error>]
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/impl/no_prelude/error_recovery.carbon b/toolchain/check/testdata/impl/no_prelude/error_recovery.carbon
index 32c316916380..4c0a7ec1a95c 100644
--- a/toolchain/check/testdata/impl/no_prelude/error_recovery.carbon
+++ b/toolchain/check/testdata/impl/no_prelude/error_recovery.carbon
@@ -13,9 +13,10 @@
 class C {}
 interface I {}
 
-// CHECK:STDERR: fail_fuzz_crash.carbon:[[@LINE+3]]:14: error: parameters of generic types must be constant [GenericParamMustBeConstant]
+// CHECK:STDERR: fail_fuzz_crash.carbon:[[@LINE+4]]:14: error: parameters of generic types must be constant [GenericParamMustBeConstant]
 // CHECK:STDERR: impl forall [T: type] C as I { }
 // CHECK:STDERR:              ^~~~~~~
+// CHECK:STDERR:
 impl forall [T: type] C as I { }
 
 // CHECK:STDOUT: --- fail_fuzz_crash.carbon
diff --git a/toolchain/check/testdata/impl/no_prelude/fail_alias.carbon b/toolchain/check/testdata/impl/no_prelude/fail_alias.carbon
index 22491e81ac02..3b81f9d77810 100644
--- a/toolchain/check/testdata/impl/no_prelude/fail_alias.carbon
+++ b/toolchain/check/testdata/impl/no_prelude/fail_alias.carbon
@@ -16,12 +16,13 @@ alias AC = C;
 
 impl AC as AI {}
 
-// CHECK:STDERR: fail_alias.carbon:[[@LINE+6]]:1: error: redefinition of `impl AC as AI` [ImplRedefinition]
+// CHECK:STDERR: fail_alias.carbon:[[@LINE+7]]:1: error: redefinition of `impl AC as AI` [ImplRedefinition]
 // CHECK:STDERR: impl AC as AI {}
 // CHECK:STDERR: ^~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_alias.carbon:[[@LINE-5]]:1: note: previous definition was here [ImplPreviousDefinition]
 // CHECK:STDERR: impl AC as AI {}
 // CHECK:STDERR: ^~~~~~~~~~~~~~~
+// CHECK:STDERR:
 impl AC as AI {}
 
 // CHECK:STDOUT: --- fail_alias.carbon
@@ -57,7 +58,7 @@ impl AC as AI {}
 // CHECK:STDOUT:     %AC.ref: type = name_ref AC, file.%AC [template = constants.%C]
 // CHECK:STDOUT:     %AI.ref: type = name_ref AI, file.%AI [template = constants.%I.type]
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %impl_witness.loc25: <witness> = impl_witness () [template = constants.%impl_witness]
+// CHECK:STDOUT:   %impl_witness.loc26: <witness> = impl_witness () [template = constants.%impl_witness]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: interface @I {
@@ -75,7 +76,7 @@ impl AC as AI {}
 // CHECK:STDOUT:
 // CHECK:STDOUT: impl @impl.2: %AC.ref as %AI.ref {
 // CHECK:STDOUT: !members:
-// CHECK:STDOUT:   witness = file.%impl_witness.loc25
+// CHECK:STDOUT:   witness = file.%impl_witness.loc26
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: class @C {
diff --git a/toolchain/check/testdata/impl/no_prelude/fail_impl_bad_assoc_const.carbon b/toolchain/check/testdata/impl/no_prelude/fail_impl_bad_assoc_const.carbon
index 40a92776d1a7..0fdc707f9e0f 100644
--- a/toolchain/check/testdata/impl/no_prelude/fail_impl_bad_assoc_const.carbon
+++ b/toolchain/check/testdata/impl/no_prelude/fail_impl_bad_assoc_const.carbon
@@ -10,12 +10,13 @@
 
 interface I { let T:! type; }
 
-// CHECK:STDERR: fail_impl_bad_assoc_const.carbon:[[@LINE+6]]:12: error: associated constant T not given a value in impl of interface I [ImplAssociatedConstantNeedsValue]
+// CHECK:STDERR: fail_impl_bad_assoc_const.carbon:[[@LINE+7]]:12: error: associated constant T not given a value in impl of interface I [ImplAssociatedConstantNeedsValue]
 // CHECK:STDERR: impl () as I {}
 // CHECK:STDERR:            ^
 // CHECK:STDERR: fail_impl_bad_assoc_const.carbon:[[@LINE-5]]:15: note: associated constant T declared here [AssociatedConstantHere]
 // CHECK:STDERR: interface I { let T:! type; }
 // CHECK:STDERR:               ^~~~~~~~~~~~~
+// CHECK:STDERR:
 impl () as I {}
 
 // CHECK:STDOUT: --- fail_impl_bad_assoc_const.carbon
@@ -35,8 +36,8 @@ impl () as I {}
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %I.decl: type = interface_decl @I [template = constants.%I.type] {} {}
 // CHECK:STDOUT:   impl_decl @impl [template] {} {
-// CHECK:STDOUT:     %.loc19_7.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc19_7.2: type = converted %.loc19_7.1, constants.%empty_tuple.type [template = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %.loc20_7.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc20_7.2: type = converted %.loc20_7.1, constants.%empty_tuple.type [template = constants.%empty_tuple.type]
 // CHECK:STDOUT:     %I.ref: type = name_ref I, file.%I.decl [template = constants.%I.type]
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %impl_witness: <witness> = impl_witness (<error>) [template = constants.%impl_witness]
@@ -53,7 +54,7 @@ impl () as I {}
 // CHECK:STDOUT:   witness = (%T)
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl: %.loc19_7.2 as %I.ref {
+// CHECK:STDOUT: impl @impl: %.loc20_7.2 as %I.ref {
 // CHECK:STDOUT: !members:
 // CHECK:STDOUT:   witness = file.%impl_witness
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/impl/no_prelude/fail_impl_bad_type.carbon b/toolchain/check/testdata/impl/no_prelude/fail_impl_bad_type.carbon
index cf5e9756a8f1..03a077f4f053 100644
--- a/toolchain/check/testdata/impl/no_prelude/fail_impl_bad_type.carbon
+++ b/toolchain/check/testdata/impl/no_prelude/fail_impl_bad_type.carbon
@@ -10,9 +10,10 @@
 
 interface I {}
 
-// CHECK:STDERR: fail_impl_bad_type.carbon:[[@LINE+3]]:6: error: `Core.ImplicitAs` implicitly referenced here, but package `Core` not found [CoreNotFound]
+// CHECK:STDERR: fail_impl_bad_type.carbon:[[@LINE+4]]:6: error: `Core.ImplicitAs` implicitly referenced here, but package `Core` not found [CoreNotFound]
 // CHECK:STDERR: impl true as I {}
 // CHECK:STDERR:      ^~~~
+// CHECK:STDERR:
 impl true as I {}
 
 // CHECK:STDOUT: --- fail_impl_bad_type.carbon
@@ -31,7 +32,7 @@ impl true as I {}
 // CHECK:STDOUT:   %I.decl: type = interface_decl @I [template = constants.%I.type] {} {}
 // CHECK:STDOUT:   impl_decl @impl [template] {} {
 // CHECK:STDOUT:     %true: bool = bool_literal true [template = constants.%true]
-// CHECK:STDOUT:     %.loc16: type = converted %true, <error> [template = <error>]
+// CHECK:STDOUT:     %.loc17: type = converted %true, <error> [template = <error>]
 // CHECK:STDOUT:     %I.ref: type = name_ref I, file.%I.decl [template = constants.%I.type]
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %impl_witness: <witness> = impl_witness () [template = constants.%impl_witness]
diff --git a/toolchain/check/testdata/impl/no_prelude/fail_undefined_interface.carbon b/toolchain/check/testdata/impl/no_prelude/fail_undefined_interface.carbon
index 8252a680b250..585bf45f1edf 100644
--- a/toolchain/check/testdata/impl/no_prelude/fail_undefined_interface.carbon
+++ b/toolchain/check/testdata/impl/no_prelude/fail_undefined_interface.carbon
@@ -28,12 +28,13 @@ library "[[@TEST_NAME]]";
 
 interface J;
 class C {}
-// CHECK:STDERR: fail_class.carbon:[[@LINE+6]]:1: error: implementation of undefined interface J [ImplOfUndefinedInterface]
+// CHECK:STDERR: fail_class.carbon:[[@LINE+7]]:1: error: implementation of undefined interface J [ImplOfUndefinedInterface]
 // CHECK:STDERR: impl C as J {}
 // CHECK:STDERR: ^~~~~~~~~~~~~
 // CHECK:STDERR: fail_class.carbon:[[@LINE-5]]:1: note: interface was forward declared here [InterfaceForwardDeclaredHere]
 // CHECK:STDERR: interface J;
 // CHECK:STDERR: ^~~~~~~~~~~~
+// CHECK:STDERR:
 impl C as J {}
 
 // CHECK:STDOUT: --- fail_empty_struct.carbon
diff --git a/toolchain/check/testdata/impl/no_prelude/generic_redeclaration.carbon b/toolchain/check/testdata/impl/no_prelude/generic_redeclaration.carbon
index 6fe09a4a9e4d..87fccd4b81a3 100644
--- a/toolchain/check/testdata/impl/no_prelude/generic_redeclaration.carbon
+++ b/toolchain/check/testdata/impl/no_prelude/generic_redeclaration.carbon
@@ -72,12 +72,13 @@ impl forall [T:! type] T as I {
   fn A() {}
 }
 
-// CHECK:STDERR: fail_redefinition_generic_regions.carbon:[[@LINE+6]]:1: error: redefinition of `impl T as I` [ImplRedefinition]
+// CHECK:STDERR: fail_redefinition_generic_regions.carbon:[[@LINE+7]]:1: error: redefinition of `impl T as I` [ImplRedefinition]
 // CHECK:STDERR: impl forall [T:! type] T as I {
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_redefinition_generic_regions.carbon:[[@LINE-7]]:1: note: previous definition was here [ImplPreviousDefinition]
 // CHECK:STDERR: impl forall [T:! type] T as I {
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 impl forall [T:! type] T as I {
   // Although not referenced, B has the same generic region index of A, and
   // makes C a different index. We used to merge, and this was a crash.
@@ -572,15 +573,15 @@ impl forall [T:! type] T as I {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %impl_witness.loc4: <witness> = impl_witness (), @impl.1(constants.%T) [symbolic = @impl.1.%impl_witness (constants.%impl_witness.1f09a1.1)]
 // CHECK:STDOUT:   impl_decl @impl.2 [template] {
-// CHECK:STDOUT:     %T.patt.loc14_14.1: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc14_14.2 (constants.%T.patt)]
-// CHECK:STDOUT:     %T.param_patt: type = value_param_pattern %T.patt.loc14_14.1, runtime_param<invalid> [symbolic = %T.patt.loc14_14.2 (constants.%T.patt)]
+// CHECK:STDOUT:     %T.patt.loc15_14.1: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc15_14.2 (constants.%T.patt)]
+// CHECK:STDOUT:     %T.param_patt: type = value_param_pattern %T.patt.loc15_14.1, runtime_param<invalid> [symbolic = %T.patt.loc15_14.2 (constants.%T.patt)]
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %T.ref: type = name_ref T, %T.loc14_14.1 [symbolic = %T.loc14_14.2 (constants.%T)]
+// CHECK:STDOUT:     %T.ref: type = name_ref T, %T.loc15_14.1 [symbolic = %T.loc15_14.2 (constants.%T)]
 // CHECK:STDOUT:     %I.ref: type = name_ref I, file.%I.decl [template = constants.%I.type]
 // CHECK:STDOUT:     %T.param: type = value_param runtime_param<invalid>
-// CHECK:STDOUT:     %T.loc14_14.1: type = bind_symbolic_name T, 0, %T.param [symbolic = %T.loc14_14.2 (constants.%T)]
+// CHECK:STDOUT:     %T.loc15_14.1: type = bind_symbolic_name T, 0, %T.param [symbolic = %T.loc15_14.2 (constants.%T)]
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %impl_witness.loc14: <witness> = impl_witness (), @impl.2(constants.%T) [symbolic = @impl.2.%impl_witness (constants.%impl_witness.1f09a1.2)]
+// CHECK:STDOUT:   %impl_witness.loc15: <witness> = impl_witness (), @impl.2(constants.%T) [symbolic = @impl.2.%impl_witness (constants.%impl_witness.1f09a1.2)]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: interface @I {
@@ -609,17 +610,17 @@ impl forall [T:! type] T as I {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: generic impl @impl.2(%T.loc14_14.1: type) {
-// CHECK:STDOUT:   %T.loc14_14.2: type = bind_symbolic_name T, 0 [symbolic = %T.loc14_14.2 (constants.%T)]
-// CHECK:STDOUT:   %T.patt.loc14_14.2: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc14_14.2 (constants.%T.patt)]
-// CHECK:STDOUT:   %impl_witness: <witness> = impl_witness (), @impl.2(%T.loc14_14.2) [symbolic = %impl_witness (constants.%impl_witness.1f09a1.2)]
+// CHECK:STDOUT: generic impl @impl.2(%T.loc15_14.1: type) {
+// CHECK:STDOUT:   %T.loc15_14.2: type = bind_symbolic_name T, 0 [symbolic = %T.loc15_14.2 (constants.%T)]
+// CHECK:STDOUT:   %T.patt.loc15_14.2: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc15_14.2 (constants.%T.patt)]
+// CHECK:STDOUT:   %impl_witness: <witness> = impl_witness (), @impl.2(%T.loc15_14.2) [symbolic = %impl_witness (constants.%impl_witness.1f09a1.2)]
 // CHECK:STDOUT:
 // CHECK:STDOUT: !definition:
-// CHECK:STDOUT:   %B.type: type = fn_type @B, @impl.2(%T.loc14_14.2) [symbolic = %B.type (constants.%B.type)]
+// CHECK:STDOUT:   %B.type: type = fn_type @B, @impl.2(%T.loc15_14.2) [symbolic = %B.type (constants.%B.type)]
 // CHECK:STDOUT:   %B: @impl.2.%B.type (%B.type) = struct_value () [symbolic = %B (constants.%B)]
-// CHECK:STDOUT:   %C.type: type = fn_type @C, @impl.2(%T.loc14_14.2) [symbolic = %C.type (constants.%C.type)]
+// CHECK:STDOUT:   %C.type: type = fn_type @C, @impl.2(%T.loc15_14.2) [symbolic = %C.type (constants.%C.type)]
 // CHECK:STDOUT:   %C: @impl.2.%C.type (%C.type) = struct_value () [symbolic = %C (constants.%C)]
-// CHECK:STDOUT:   %D.type: type = fn_type @D, @impl.2(%T.loc14_14.2) [symbolic = %D.type (constants.%D.type)]
+// CHECK:STDOUT:   %D.type: type = fn_type @D, @impl.2(%T.loc15_14.2) [symbolic = %D.type (constants.%D.type)]
 // CHECK:STDOUT:   %D: @impl.2.%D.type (%D.type) = struct_value () [symbolic = %D (constants.%D)]
 // CHECK:STDOUT:
 // CHECK:STDOUT:   impl: %T.ref as %I.ref {
@@ -628,8 +629,8 @@ impl forall [T:! type] T as I {
 // CHECK:STDOUT:       %return.patt: %empty_tuple.type = return_slot_pattern
 // CHECK:STDOUT:       %return.param_patt: %empty_tuple.type = out_param_pattern %return.patt, runtime_param0
 // CHECK:STDOUT:     } {
-// CHECK:STDOUT:       %.loc18_14.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:       %.loc18_14.2: type = converted %.loc18_14.1, constants.%empty_tuple.type [template = constants.%empty_tuple.type]
+// CHECK:STDOUT:       %.loc19_14.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:       %.loc19_14.2: type = converted %.loc19_14.1, constants.%empty_tuple.type [template = constants.%empty_tuple.type]
 // CHECK:STDOUT:       %return.param: ref %empty_tuple.type = out_param runtime_param0
 // CHECK:STDOUT:       %return: ref %empty_tuple.type = return_slot %return.param
 // CHECK:STDOUT:     }
@@ -637,8 +638,8 @@ impl forall [T:! type] T as I {
 // CHECK:STDOUT:       %return.patt: %empty_tuple.type = return_slot_pattern
 // CHECK:STDOUT:       %return.param_patt: %empty_tuple.type = out_param_pattern %return.patt, runtime_param0
 // CHECK:STDOUT:     } {
-// CHECK:STDOUT:       %.loc19_14.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:       %.loc19_14.2: type = converted %.loc19_14.1, constants.%empty_tuple.type [template = constants.%empty_tuple.type]
+// CHECK:STDOUT:       %.loc20_14.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:       %.loc20_14.2: type = converted %.loc20_14.1, constants.%empty_tuple.type [template = constants.%empty_tuple.type]
 // CHECK:STDOUT:       %return.param: ref %empty_tuple.type = out_param runtime_param0
 // CHECK:STDOUT:       %return: ref %empty_tuple.type = return_slot %return.param
 // CHECK:STDOUT:     }
@@ -647,7 +648,7 @@ impl forall [T:! type] T as I {
 // CHECK:STDOUT:     .B = %B.decl
 // CHECK:STDOUT:     .C = %C.decl
 // CHECK:STDOUT:     .D = %D.decl
-// CHECK:STDOUT:     witness = file.%impl_witness.loc14
+// CHECK:STDOUT:     witness = file.%impl_witness.loc15
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -660,7 +661,7 @@ impl forall [T:! type] T as I {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: generic fn @B(@impl.2.%T.loc14_14.1: type) {
+// CHECK:STDOUT: generic fn @B(@impl.2.%T.loc15_14.1: type) {
 // CHECK:STDOUT: !definition:
 // CHECK:STDOUT:
 // CHECK:STDOUT:   fn() {
@@ -669,36 +670,36 @@ impl forall [T:! type] T as I {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: generic fn @C(@impl.2.%T.loc14_14.1: type) {
+// CHECK:STDOUT: generic fn @C(@impl.2.%T.loc15_14.1: type) {
 // CHECK:STDOUT: !definition:
 // CHECK:STDOUT:
 // CHECK:STDOUT:   fn() -> %empty_tuple.type {
 // CHECK:STDOUT:   !entry:
-// CHECK:STDOUT:     %.loc18_26: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc19_26: %empty_tuple.type = tuple_literal ()
 // CHECK:STDOUT:     %empty_tuple: %empty_tuple.type = tuple_value () [template = constants.%empty_tuple]
-// CHECK:STDOUT:     %.loc18_27: %empty_tuple.type = converted %.loc18_26, %empty_tuple [template = constants.%empty_tuple]
-// CHECK:STDOUT:     return %.loc18_27
+// CHECK:STDOUT:     %.loc19_27: %empty_tuple.type = converted %.loc19_26, %empty_tuple [template = constants.%empty_tuple]
+// CHECK:STDOUT:     return %.loc19_27
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: generic fn @D(@impl.2.%T.loc14_14.1: type) {
+// CHECK:STDOUT: generic fn @D(@impl.2.%T.loc15_14.1: type) {
 // CHECK:STDOUT: !definition:
 // CHECK:STDOUT:   %T: type = bind_symbolic_name T, 0 [symbolic = %T (constants.%T)]
 // CHECK:STDOUT:   %C.type: type = fn_type @C, @impl.2(%T) [symbolic = %C.type (constants.%C.type)]
 // CHECK:STDOUT:   %C: @D.%C.type (%C.type) = struct_value () [symbolic = %C (constants.%C)]
-// CHECK:STDOUT:   %C.specific_fn.loc20_12.2: <specific function> = specific_function %C, @C(%T) [symbolic = %C.specific_fn.loc20_12.2 (constants.%C.specific_fn)]
+// CHECK:STDOUT:   %C.specific_fn.loc21_12.2: <specific function> = specific_function %C, @C(%T) [symbolic = %C.specific_fn.loc21_12.2 (constants.%C.specific_fn)]
 // CHECK:STDOUT:
 // CHECK:STDOUT:   fn() -> %empty_tuple.type {
 // CHECK:STDOUT:   !entry:
-// CHECK:STDOUT:     %.loc20_12: @D.%C.type (%C.type) = specific_constant @impl.2.%C.decl, @impl.2(constants.%T) [symbolic = %C (constants.%C)]
-// CHECK:STDOUT:     %C.ref: @D.%C.type (%C.type) = name_ref C, %.loc20_12 [symbolic = %C (constants.%C)]
-// CHECK:STDOUT:     %C.specific_fn.loc20_12.1: <specific function> = specific_function %C.ref, @C(constants.%T) [symbolic = %C.specific_fn.loc20_12.2 (constants.%C.specific_fn)]
-// CHECK:STDOUT:     %C.call: init %empty_tuple.type = call %C.specific_fn.loc20_12.1()
-// CHECK:STDOUT:     %.loc20_14.1: ref %empty_tuple.type = temporary_storage
-// CHECK:STDOUT:     %.loc20_14.2: ref %empty_tuple.type = temporary %.loc20_14.1, %C.call
+// CHECK:STDOUT:     %.loc21_12: @D.%C.type (%C.type) = specific_constant @impl.2.%C.decl, @impl.2(constants.%T) [symbolic = %C (constants.%C)]
+// CHECK:STDOUT:     %C.ref: @D.%C.type (%C.type) = name_ref C, %.loc21_12 [symbolic = %C (constants.%C)]
+// CHECK:STDOUT:     %C.specific_fn.loc21_12.1: <specific function> = specific_function %C.ref, @C(constants.%T) [symbolic = %C.specific_fn.loc21_12.2 (constants.%C.specific_fn)]
+// CHECK:STDOUT:     %C.call: init %empty_tuple.type = call %C.specific_fn.loc21_12.1()
+// CHECK:STDOUT:     %.loc21_14.1: ref %empty_tuple.type = temporary_storage
+// CHECK:STDOUT:     %.loc21_14.2: ref %empty_tuple.type = temporary %.loc21_14.1, %C.call
 // CHECK:STDOUT:     %tuple: %empty_tuple.type = tuple_value () [template = constants.%empty_tuple]
-// CHECK:STDOUT:     %.loc20_15: %empty_tuple.type = converted %C.call, %tuple [template = constants.%empty_tuple]
-// CHECK:STDOUT:     return %.loc20_15
+// CHECK:STDOUT:     %.loc21_15: %empty_tuple.type = converted %C.call, %tuple [template = constants.%empty_tuple]
+// CHECK:STDOUT:     return %.loc21_15
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -717,8 +718,8 @@ impl forall [T:! type] T as I {
 // CHECK:STDOUT: specific @A(constants.%T) {}
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @impl.2(constants.%T) {
-// CHECK:STDOUT:   %T.loc14_14.2 => constants.%T
-// CHECK:STDOUT:   %T.patt.loc14_14.2 => constants.%T
+// CHECK:STDOUT:   %T.loc15_14.2 => constants.%T
+// CHECK:STDOUT:   %T.patt.loc15_14.2 => constants.%T
 // CHECK:STDOUT:   %impl_witness => constants.%impl_witness.1f09a1.2
 // CHECK:STDOUT:
 // CHECK:STDOUT: !definition:
@@ -730,7 +731,7 @@ impl forall [T:! type] T as I {
 // CHECK:STDOUT:   %D => constants.%D
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: specific @impl.2(%T.loc14_14.2) {}
+// CHECK:STDOUT: specific @impl.2(%T.loc15_14.2) {}
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @B(constants.%T) {}
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/impl/no_prelude/impl_assoc_const.carbon b/toolchain/check/testdata/impl/no_prelude/impl_assoc_const.carbon
index 85327ab1b9d8..9920234e6479 100644
--- a/toolchain/check/testdata/impl/no_prelude/impl_assoc_const.carbon
+++ b/toolchain/check/testdata/impl/no_prelude/impl_assoc_const.carbon
@@ -132,13 +132,14 @@ library "[[@TEST_NAME]]";
 
 interface L4 { let W4:! type; }
 
-// CHECK:STDERR: fail_two_different_both_bad.carbon:[[@LINE+7]]:27: error: name `BAD7` not found [NameNotFound]
+// CHECK:STDERR: fail_two_different_both_bad.carbon:[[@LINE+8]]:27: error: name `BAD7` not found [NameNotFound]
 // CHECK:STDERR: impl () as L4 where .W4 = BAD7 and .W4 = BAD8 {}
 // CHECK:STDERR:                           ^~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_two_different_both_bad.carbon:[[@LINE+3]]:42: error: name `BAD8` not found [NameNotFound]
+// CHECK:STDERR: fail_two_different_both_bad.carbon:[[@LINE+4]]:42: error: name `BAD8` not found [NameNotFound]
 // CHECK:STDERR: impl () as L4 where .W4 = BAD7 and .W4 = BAD8 {}
 // CHECK:STDERR:                                          ^~~~
+// CHECK:STDERR:
 impl () as L4 where .W4 = BAD7 and .W4 = BAD8 {}
 
 // --- repeated.carbon
@@ -774,23 +775,23 @@ impl () as N where .Y = {.a = {}} { }
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %L4.decl: type = interface_decl @L4 [template = constants.%L4.type] {} {}
 // CHECK:STDOUT:   impl_decl @impl [template] {} {
-// CHECK:STDOUT:     %.loc12_7.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc12_7.2: type = converted %.loc12_7.1, constants.%empty_tuple.type [template = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %.loc13_7.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc13_7.2: type = converted %.loc13_7.1, constants.%empty_tuple.type [template = constants.%empty_tuple.type]
 // CHECK:STDOUT:     %L4.ref: type = name_ref L4, file.%L4.decl [template = constants.%L4.type]
 // CHECK:STDOUT:     %.Self: %L4.type = bind_symbolic_name .Self [symbolic = constants.%.Self]
-// CHECK:STDOUT:     %.Self.ref.loc12_21: %L4.type = name_ref .Self, %.Self [symbolic = constants.%.Self]
-// CHECK:STDOUT:     %W4.ref.loc12_21: %assoc_type = name_ref W4, @L4.%assoc0 [template = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_wit.loc12_21: <witness> = facet_access_witness %.Self.ref.loc12_21 [symbolic = constants.%.Self.as_wit]
-// CHECK:STDOUT:     %impl.elem0.loc12_21: type = impl_witness_access %.Self.as_wit.loc12_21, element0 [symbolic = constants.%impl.elem0]
+// CHECK:STDOUT:     %.Self.ref.loc13_21: %L4.type = name_ref .Self, %.Self [symbolic = constants.%.Self]
+// CHECK:STDOUT:     %W4.ref.loc13_21: %assoc_type = name_ref W4, @L4.%assoc0 [template = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_wit.loc13_21: <witness> = facet_access_witness %.Self.ref.loc13_21 [symbolic = constants.%.Self.as_wit]
+// CHECK:STDOUT:     %impl.elem0.loc13_21: type = impl_witness_access %.Self.as_wit.loc13_21, element0 [symbolic = constants.%impl.elem0]
 // CHECK:STDOUT:     %BAD7.ref: <error> = name_ref BAD7, <error> [template = <error>]
-// CHECK:STDOUT:     %.Self.ref.loc12_36: %L4.type = name_ref .Self, %.Self [symbolic = constants.%.Self]
-// CHECK:STDOUT:     %W4.ref.loc12_36: %assoc_type = name_ref W4, @L4.%assoc0 [template = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_wit.loc12_36: <witness> = facet_access_witness %.Self.ref.loc12_36 [symbolic = constants.%.Self.as_wit]
-// CHECK:STDOUT:     %impl.elem0.loc12_36: type = impl_witness_access %.Self.as_wit.loc12_36, element0 [symbolic = constants.%impl.elem0]
+// CHECK:STDOUT:     %.Self.ref.loc13_36: %L4.type = name_ref .Self, %.Self [symbolic = constants.%.Self]
+// CHECK:STDOUT:     %W4.ref.loc13_36: %assoc_type = name_ref W4, @L4.%assoc0 [template = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_wit.loc13_36: <witness> = facet_access_witness %.Self.ref.loc13_36 [symbolic = constants.%.Self.as_wit]
+// CHECK:STDOUT:     %impl.elem0.loc13_36: type = impl_witness_access %.Self.as_wit.loc13_36, element0 [symbolic = constants.%impl.elem0]
 // CHECK:STDOUT:     %BAD8.ref: <error> = name_ref BAD8, <error> [template = <error>]
-// CHECK:STDOUT:     %.loc12_15: type = where_expr %.Self [template = <error>] {
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc12_21, <error>
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc12_36, <error>
+// CHECK:STDOUT:     %.loc13_15: type = where_expr %.Self [template = <error>] {
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc13_21, <error>
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc13_36, <error>
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
@@ -806,7 +807,7 @@ impl () as N where .Y = {.a = {}} { }
 // CHECK:STDOUT:   witness = (%W4)
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl: %.loc12_7.2 as %.loc12_15 {
+// CHECK:STDOUT: impl @impl: %.loc13_7.2 as %.loc13_15 {
 // CHECK:STDOUT: !members:
 // CHECK:STDOUT:   witness = <error>
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/impl/no_prelude/impl_self_as.carbon b/toolchain/check/testdata/impl/no_prelude/impl_self_as.carbon
index be455031a405..c7e6082cf19b 100644
--- a/toolchain/check/testdata/impl/no_prelude/impl_self_as.carbon
+++ b/toolchain/check/testdata/impl/no_prelude/impl_self_as.carbon
@@ -172,9 +172,10 @@ class C4(A:! type) {
   impl forall [B5:! type] as J5(B5);
   impl forall [B5:! type] C4(A) as J5(B5) {}
 
-  // CHECK:STDERR: fail_no_match.carbon:[[@LINE+3]]:3: error: impl declared but not defined [ImplMissingDefinition]
+  // CHECK:STDERR: fail_no_match.carbon:[[@LINE+4]]:3: error: impl declared but not defined [ImplMissingDefinition]
   // CHECK:STDERR:   impl forall [B6:! type] Self as J6(B6);
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   impl forall [B6:! type] Self as J6(B6);
   impl forall [B6:! type] C4(A) as J6(B6) {}
 }
diff --git a/toolchain/check/testdata/impl/no_prelude/impl_where_redecl.carbon b/toolchain/check/testdata/impl/no_prelude/impl_where_redecl.carbon
index ae50c1ca9090..b228186da227 100644
--- a/toolchain/check/testdata/impl/no_prelude/impl_where_redecl.carbon
+++ b/toolchain/check/testdata/impl/no_prelude/impl_where_redecl.carbon
@@ -50,8 +50,9 @@ library "[[@TEST_NAME]]";
 
 interface L {}
 
-// CHECK:STDERR: fail_other_nesting.carbon:[[@LINE+3]]:1: error: impl declared but not defined [ImplMissingDefinition]
+// CHECK:STDERR: fail_other_nesting.carbon:[[@LINE+4]]:1: error: impl declared but not defined [ImplMissingDefinition]
 // CHECK:STDERR: impl () as (L where .Self impls type) where .Self impls type;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 impl () as (L where .Self impls type) where .Self impls type;
 impl () as L {}
diff --git a/toolchain/check/testdata/impl/no_prelude/import_generic.carbon b/toolchain/check/testdata/impl/no_prelude/import_generic.carbon
index 78f78b0d77d6..b00d44131ed2 100644
--- a/toolchain/check/testdata/impl/no_prelude/import_generic.carbon
+++ b/toolchain/check/testdata/impl/no_prelude/import_generic.carbon
@@ -91,9 +91,10 @@ impl forall [T:! type] D as J(T) {}
 // CHECK:STDERR:
 impl forall [T:! type] D as J(T*);
 
-// CHECK:STDERR: fail_import_generic_decl.impl.carbon:[[@LINE+3]]:1: error: redeclaration of imported impl [RedeclImportedImpl]
+// CHECK:STDERR: fail_import_generic_decl.impl.carbon:[[@LINE+4]]:1: error: redeclaration of imported impl [RedeclImportedImpl]
 // CHECK:STDERR: impl forall [T:! type] D as J(T*) {}
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 impl forall [T:! type] D as J(T*) {}
 
 // CHECK:STDOUT: --- import_generic.carbon
@@ -786,18 +787,18 @@ impl forall [T:! type] D as J(T*) {}
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %impl_witness.loc20: <witness> = impl_witness (), @impl.5(constants.%T) [symbolic = @impl.5.%impl_witness (constants.%impl_witness.b80f53.2)]
 // CHECK:STDOUT:   impl_decl @impl.6 [template] {
-// CHECK:STDOUT:     %T.patt.loc25_14.1: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc25_14.2 (constants.%T.patt)]
-// CHECK:STDOUT:     %T.param_patt: type = value_param_pattern %T.patt.loc25_14.1, runtime_param<invalid> [symbolic = %T.patt.loc25_14.2 (constants.%T.patt)]
+// CHECK:STDOUT:     %T.patt.loc26_14.1: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc26_14.2 (constants.%T.patt)]
+// CHECK:STDOUT:     %T.param_patt: type = value_param_pattern %T.patt.loc26_14.1, runtime_param<invalid> [symbolic = %T.patt.loc26_14.2 (constants.%T.patt)]
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %D.ref: type = name_ref D, imports.%import_ref.b0a [template = constants.%D]
 // CHECK:STDOUT:     %J.ref: %J.type.2b8 = name_ref J, imports.%import_ref.0eb [template = constants.%J.generic]
-// CHECK:STDOUT:     %T.ref: type = name_ref T, %T.loc25_14.1 [symbolic = %T.loc25_14.2 (constants.%T)]
-// CHECK:STDOUT:     %ptr.loc25_32.1: type = ptr_type %T [symbolic = %ptr.loc25_32.2 (constants.%ptr)]
-// CHECK:STDOUT:     %J.type.loc25_33.1: type = facet_type <@J, @J(constants.%ptr)> [symbolic = %J.type.loc25_33.2 (constants.%J.type.628)]
+// CHECK:STDOUT:     %T.ref: type = name_ref T, %T.loc26_14.1 [symbolic = %T.loc26_14.2 (constants.%T)]
+// CHECK:STDOUT:     %ptr.loc26_32.1: type = ptr_type %T [symbolic = %ptr.loc26_32.2 (constants.%ptr)]
+// CHECK:STDOUT:     %J.type.loc26_33.1: type = facet_type <@J, @J(constants.%ptr)> [symbolic = %J.type.loc26_33.2 (constants.%J.type.628)]
 // CHECK:STDOUT:     %T.param: type = value_param runtime_param<invalid>
-// CHECK:STDOUT:     %T.loc25_14.1: type = bind_symbolic_name T, 0, %T.param [symbolic = %T.loc25_14.2 (constants.%T)]
+// CHECK:STDOUT:     %T.loc26_14.1: type = bind_symbolic_name T, 0, %T.param [symbolic = %T.loc26_14.2 (constants.%T)]
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %impl_witness.loc25: <witness> = impl_witness (), @impl.6(constants.%T) [symbolic = @impl.6.%impl_witness (constants.%impl_witness.b80f53.3)]
+// CHECK:STDOUT:   %impl_witness.loc26: <witness> = impl_witness (), @impl.6(constants.%T) [symbolic = @impl.6.%impl_witness (constants.%impl_witness.b80f53.3)]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: generic interface @J(constants.%T: type) [from "fail_import_generic_decl.carbon"] {
@@ -872,19 +873,19 @@ impl forall [T:! type] D as J(T*) {}
 // CHECK:STDOUT:   impl: %D.ref as %J.type.loc20_33.1;
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: generic impl @impl.6(%T.loc25_14.1: type) {
-// CHECK:STDOUT:   %T.loc25_14.2: type = bind_symbolic_name T, 0 [symbolic = %T.loc25_14.2 (constants.%T)]
-// CHECK:STDOUT:   %T.patt.loc25_14.2: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc25_14.2 (constants.%T.patt)]
-// CHECK:STDOUT:   %ptr.loc25_32.2: type = ptr_type @impl.6.%T.loc25_14.2 (%T) [symbolic = %ptr.loc25_32.2 (constants.%ptr)]
-// CHECK:STDOUT:   %J.type.loc25_33.2: type = facet_type <@J, @J(%ptr.loc25_32.2)> [symbolic = %J.type.loc25_33.2 (constants.%J.type.628)]
-// CHECK:STDOUT:   %require_complete: <witness> = require_complete_type @impl.6.%J.type.loc25_33.2 (%J.type.628) [symbolic = %require_complete (constants.%require_complete.c60)]
-// CHECK:STDOUT:   %impl_witness: <witness> = impl_witness (), @impl.6(%T.loc25_14.2) [symbolic = %impl_witness (constants.%impl_witness.b80f53.3)]
+// CHECK:STDOUT: generic impl @impl.6(%T.loc26_14.1: type) {
+// CHECK:STDOUT:   %T.loc26_14.2: type = bind_symbolic_name T, 0 [symbolic = %T.loc26_14.2 (constants.%T)]
+// CHECK:STDOUT:   %T.patt.loc26_14.2: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc26_14.2 (constants.%T.patt)]
+// CHECK:STDOUT:   %ptr.loc26_32.2: type = ptr_type @impl.6.%T.loc26_14.2 (%T) [symbolic = %ptr.loc26_32.2 (constants.%ptr)]
+// CHECK:STDOUT:   %J.type.loc26_33.2: type = facet_type <@J, @J(%ptr.loc26_32.2)> [symbolic = %J.type.loc26_33.2 (constants.%J.type.628)]
+// CHECK:STDOUT:   %require_complete: <witness> = require_complete_type @impl.6.%J.type.loc26_33.2 (%J.type.628) [symbolic = %require_complete (constants.%require_complete.c60)]
+// CHECK:STDOUT:   %impl_witness: <witness> = impl_witness (), @impl.6(%T.loc26_14.2) [symbolic = %impl_witness (constants.%impl_witness.b80f53.3)]
 // CHECK:STDOUT:
 // CHECK:STDOUT: !definition:
 // CHECK:STDOUT:
-// CHECK:STDOUT:   impl: %D.ref as %J.type.loc25_33.1 {
+// CHECK:STDOUT:   impl: %D.ref as %J.type.loc26_33.1 {
 // CHECK:STDOUT:   !members:
-// CHECK:STDOUT:     witness = file.%impl_witness.loc25
+// CHECK:STDOUT:     witness = file.%impl_witness.loc26
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -975,15 +976,15 @@ impl forall [T:! type] D as J(T*) {}
 // CHECK:STDOUT: specific @impl.5(%T.loc20_14.2) {}
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @impl.6(constants.%T) {
-// CHECK:STDOUT:   %T.loc25_14.2 => constants.%T
-// CHECK:STDOUT:   %T.patt.loc25_14.2 => constants.%T
-// CHECK:STDOUT:   %ptr.loc25_32.2 => constants.%ptr
-// CHECK:STDOUT:   %J.type.loc25_33.2 => constants.%J.type.628
+// CHECK:STDOUT:   %T.loc26_14.2 => constants.%T
+// CHECK:STDOUT:   %T.patt.loc26_14.2 => constants.%T
+// CHECK:STDOUT:   %ptr.loc26_32.2 => constants.%ptr
+// CHECK:STDOUT:   %J.type.loc26_33.2 => constants.%J.type.628
 // CHECK:STDOUT:   %require_complete => constants.%require_complete.c60
 // CHECK:STDOUT:   %impl_witness => constants.%impl_witness.b80f53.3
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: specific @J(@impl.6.%ptr.loc25_32.2) {}
+// CHECK:STDOUT: specific @J(@impl.6.%ptr.loc26_32.2) {}
 // CHECK:STDOUT:
-// CHECK:STDOUT: specific @impl.6(%T.loc25_14.2) {}
+// CHECK:STDOUT: specific @impl.6(%T.loc26_14.2) {}
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/impl/no_prelude/import_interface_assoc_const.carbon b/toolchain/check/testdata/impl/no_prelude/import_interface_assoc_const.carbon
index 14dad150eff6..09c113e958af 100644
--- a/toolchain/check/testdata/impl/no_prelude/import_interface_assoc_const.carbon
+++ b/toolchain/check/testdata/impl/no_prelude/import_interface_assoc_const.carbon
@@ -148,13 +148,14 @@ import library "interface";
 
 class CA { }
 
-// CHECK:STDERR: fail_two_different_both_bad.carbon:[[@LINE+7]]:25: error: name `BAD7` not found [NameNotFound]
+// CHECK:STDERR: fail_two_different_both_bad.carbon:[[@LINE+8]]:25: error: name `BAD7` not found [NameNotFound]
 // CHECK:STDERR: impl CA as I where .T = BAD7 and .T = BAD8 { }
 // CHECK:STDERR:                         ^~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_two_different_both_bad.carbon:[[@LINE+3]]:39: error: name `BAD8` not found [NameNotFound]
+// CHECK:STDERR: fail_two_different_both_bad.carbon:[[@LINE+4]]:39: error: name `BAD8` not found [NameNotFound]
 // CHECK:STDERR: impl CA as I where .T = BAD7 and .T = BAD8 { }
 // CHECK:STDERR:                                       ^~~~
+// CHECK:STDERR:
 impl CA as I where .T = BAD7 and .T = BAD8 { }
 
 // --- repeated.carbon
@@ -994,19 +995,19 @@ impl CC as NonType where .Y = {.a = {}} { }
 // CHECK:STDOUT:     %CA.ref: type = name_ref CA, file.%CA.decl [template = constants.%CA]
 // CHECK:STDOUT:     %I.ref: type = name_ref I, imports.%import_ref.df2 [template = constants.%I.type]
 // CHECK:STDOUT:     %.Self: %I.type = bind_symbolic_name .Self [symbolic = constants.%.Self]
-// CHECK:STDOUT:     %.Self.ref.loc13_20: %I.type = name_ref .Self, %.Self [symbolic = constants.%.Self]
-// CHECK:STDOUT:     %T.ref.loc13_20: %assoc_type = name_ref T, imports.%import_ref.15c [template = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_wit.loc13_20: <witness> = facet_access_witness %.Self.ref.loc13_20 [symbolic = constants.%.Self.as_wit]
-// CHECK:STDOUT:     %impl.elem0.loc13_20: type = impl_witness_access %.Self.as_wit.loc13_20, element0 [symbolic = constants.%impl.elem0]
+// CHECK:STDOUT:     %.Self.ref.loc14_20: %I.type = name_ref .Self, %.Self [symbolic = constants.%.Self]
+// CHECK:STDOUT:     %T.ref.loc14_20: %assoc_type = name_ref T, imports.%import_ref.15c [template = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_wit.loc14_20: <witness> = facet_access_witness %.Self.ref.loc14_20 [symbolic = constants.%.Self.as_wit]
+// CHECK:STDOUT:     %impl.elem0.loc14_20: type = impl_witness_access %.Self.as_wit.loc14_20, element0 [symbolic = constants.%impl.elem0]
 // CHECK:STDOUT:     %BAD7.ref: <error> = name_ref BAD7, <error> [template = <error>]
-// CHECK:STDOUT:     %.Self.ref.loc13_34: %I.type = name_ref .Self, %.Self [symbolic = constants.%.Self]
-// CHECK:STDOUT:     %T.ref.loc13_34: %assoc_type = name_ref T, imports.%import_ref.15c [template = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_wit.loc13_34: <witness> = facet_access_witness %.Self.ref.loc13_34 [symbolic = constants.%.Self.as_wit]
-// CHECK:STDOUT:     %impl.elem0.loc13_34: type = impl_witness_access %.Self.as_wit.loc13_34, element0 [symbolic = constants.%impl.elem0]
+// CHECK:STDOUT:     %.Self.ref.loc14_34: %I.type = name_ref .Self, %.Self [symbolic = constants.%.Self]
+// CHECK:STDOUT:     %T.ref.loc14_34: %assoc_type = name_ref T, imports.%import_ref.15c [template = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_wit.loc14_34: <witness> = facet_access_witness %.Self.ref.loc14_34 [symbolic = constants.%.Self.as_wit]
+// CHECK:STDOUT:     %impl.elem0.loc14_34: type = impl_witness_access %.Self.as_wit.loc14_34, element0 [symbolic = constants.%impl.elem0]
 // CHECK:STDOUT:     %BAD8.ref: <error> = name_ref BAD8, <error> [template = <error>]
-// CHECK:STDOUT:     %.loc13: type = where_expr %.Self [template = <error>] {
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc13_20, <error>
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc13_34, <error>
+// CHECK:STDOUT:     %.loc14: type = where_expr %.Self [template = <error>] {
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc14_20, <error>
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc14_34, <error>
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
@@ -1018,7 +1019,7 @@ impl CC as NonType where .Y = {.a = {}} { }
 // CHECK:STDOUT:   witness = (imports.%import_ref.08d)
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl: %CA.ref as %.loc13 {
+// CHECK:STDOUT: impl @impl: %CA.ref as %.loc14 {
 // CHECK:STDOUT: !members:
 // CHECK:STDOUT:   witness = <error>
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/impl/no_prelude/import_use_generic.carbon b/toolchain/check/testdata/impl/no_prelude/import_use_generic.carbon
index 499a877374bd..847026a73723 100644
--- a/toolchain/check/testdata/impl/no_prelude/import_use_generic.carbon
+++ b/toolchain/check/testdata/impl/no_prelude/import_use_generic.carbon
@@ -30,13 +30,14 @@ import library "import_generic";
 
 var c: C({}) = {};
 // We're just checking that this doesn't crash. It's not expected to compile.
-// CHECK:STDERR: fail_use_in_fn_decl.carbon:[[@LINE+7]]:11: error: `Core.ImplicitAs` implicitly referenced here, but package `Core` not found [CoreNotFound]
+// CHECK:STDERR: fail_use_in_fn_decl.carbon:[[@LINE+8]]:11: error: `Core.ImplicitAs` implicitly referenced here, but package `Core` not found [CoreNotFound]
 // CHECK:STDERR: fn F() -> c.(I.F)() {}
 // CHECK:STDERR:           ^~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_use_in_fn_decl.carbon:[[@LINE+3]]:22: error: missing `return` at end of function with declared return type [MissingReturnStatement]
+// CHECK:STDERR: fail_use_in_fn_decl.carbon:[[@LINE+4]]:22: error: missing `return` at end of function with declared return type [MissingReturnStatement]
 // CHECK:STDERR: fn F() -> c.(I.F)() {}
 // CHECK:STDERR:                      ^
+// CHECK:STDERR:
 fn F() -> c.(I.F)() {}
 
 // CHECK:STDOUT: --- import_generic.carbon
@@ -233,9 +234,9 @@ fn F() -> c.(I.F)() {}
 // CHECK:STDOUT:     %impl.elem0: %F.type.cf0 = impl_witness_access constants.%impl_witness.02b, element0 [template = constants.%F.9e6]
 // CHECK:STDOUT:     %F.specific_fn: <specific function> = specific_function %impl.elem0, @F.2(constants.%empty_struct_type) [template = constants.%F.specific_fn]
 // CHECK:STDOUT:     %F.call: init %empty_tuple.type = call %F.specific_fn()
-// CHECK:STDOUT:     %.loc15_19.1: ref %empty_tuple.type = temporary_storage
-// CHECK:STDOUT:     %.loc15_19.2: ref %empty_tuple.type = temporary %.loc15_19.1, %F.call
-// CHECK:STDOUT:     %.loc15_19.3: type = converted %F.call, <error> [template = <error>]
+// CHECK:STDOUT:     %.loc16_19.1: ref %empty_tuple.type = temporary_storage
+// CHECK:STDOUT:     %.loc16_19.2: ref %empty_tuple.type = temporary %.loc16_19.1, %F.call
+// CHECK:STDOUT:     %.loc16_19.3: type = converted %F.call, <error> [template = <error>]
 // CHECK:STDOUT:     %return.param: ref <error> = out_param runtime_param0
 // CHECK:STDOUT:     %return: ref <error> = return_slot %return.param
 // CHECK:STDOUT:   }
diff --git a/toolchain/check/testdata/impl/no_prelude/interface_args.carbon b/toolchain/check/testdata/impl/no_prelude/interface_args.carbon
index 45e97612021e..277dc4bab0ba 100644
--- a/toolchain/check/testdata/impl/no_prelude/interface_args.carbon
+++ b/toolchain/check/testdata/impl/no_prelude/interface_args.carbon
@@ -72,9 +72,10 @@ impl library "[[@TEST_NAME]]";
 class C {}
 
 fn MakeC(a: A) -> C {
-  // CHECK:STDERR: fail_factory.impl.carbon:[[@LINE+3]]:10: error: cannot access member of interface `Factory(C)` in type `A` that does not implement that interface [MissingImplInMemberAccess]
+  // CHECK:STDERR: fail_factory.impl.carbon:[[@LINE+4]]:10: error: cannot access member of interface `Factory(C)` in type `A` that does not implement that interface [MissingImplInMemberAccess]
   // CHECK:STDERR:   return a.(Factory(C).Make)();
   // CHECK:STDERR:          ^~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   return a.(Factory(C).Make)();
 }
 
@@ -965,10 +966,10 @@ fn MakeC(a: A) -> C {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %a.ref: %A = name_ref a, %a
 // CHECK:STDOUT:   %Factory.ref: %Factory.type.1a8 = name_ref Factory, imports.%import_ref.e3d [template = constants.%Factory.generic]
-// CHECK:STDOUT:   %C.ref.loc10: type = name_ref C, file.%C.decl [template = constants.%C]
+// CHECK:STDOUT:   %C.ref.loc11: type = name_ref C, file.%C.decl [template = constants.%C]
 // CHECK:STDOUT:   %Factory.type: type = facet_type <@Factory, @Factory(constants.%C)> [template = constants.%Factory.type.5c5]
-// CHECK:STDOUT:   %.loc10: %Make.assoc_type.2ea = specific_constant imports.%import_ref.b0a, @Factory(constants.%C) [template = constants.%assoc0.9a3]
-// CHECK:STDOUT:   %Make.ref: %Make.assoc_type.2ea = name_ref Make, %.loc10 [template = constants.%assoc0.9a3]
+// CHECK:STDOUT:   %.loc11: %Make.assoc_type.2ea = specific_constant imports.%import_ref.b0a, @Factory(constants.%C) [template = constants.%assoc0.9a3]
+// CHECK:STDOUT:   %Make.ref: %Make.assoc_type.2ea = name_ref Make, %.loc11 [template = constants.%assoc0.9a3]
 // CHECK:STDOUT:   return <error> to %return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/impl/no_prelude/no_definition_in_impl_file.carbon b/toolchain/check/testdata/impl/no_prelude/no_definition_in_impl_file.carbon
index b6ae66928c72..66a70b472160 100644
--- a/toolchain/check/testdata/impl/no_prelude/no_definition_in_impl_file.carbon
+++ b/toolchain/check/testdata/impl/no_prelude/no_definition_in_impl_file.carbon
@@ -94,9 +94,10 @@ impl library "[[@TEST_NAME]]";
 
 interface D {}
 
-// CHECK:STDERR: fail_decl_only_in_impl.impl.carbon:[[@LINE+3]]:1: error: impl declared but not defined [ImplMissingDefinition]
+// CHECK:STDERR: fail_decl_only_in_impl.impl.carbon:[[@LINE+4]]:1: error: impl declared but not defined [ImplMissingDefinition]
 // CHECK:STDERR: impl () as D;
 // CHECK:STDERR: ^~~~~~~~~~~~~
+// CHECK:STDERR:
 impl () as D;
 
 // CHECK:STDOUT: --- fail_decl_in_api_definition_in_impl.carbon
@@ -357,8 +358,8 @@ impl () as D;
 // CHECK:STDOUT:   %default.import.loc2_6.2 = import <invalid>
 // CHECK:STDOUT:   %D.decl: type = interface_decl @D [template = constants.%D.type] {} {}
 // CHECK:STDOUT:   impl_decl @impl [template] {} {
-// CHECK:STDOUT:     %.loc9_7.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc9_7.2: type = converted %.loc9_7.1, constants.%empty_tuple.type [template = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %.loc10_7.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc10_7.2: type = converted %.loc10_7.1, constants.%empty_tuple.type [template = constants.%empty_tuple.type]
 // CHECK:STDOUT:     %D.ref: type = name_ref D, file.%D.decl [template = constants.%D.type]
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %impl_witness: <witness> = impl_witness () [template = constants.%impl_witness]
@@ -372,5 +373,5 @@ impl () as D;
 // CHECK:STDOUT:   witness = ()
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl: %.loc9_7.2 as %D.ref;
+// CHECK:STDOUT: impl @impl: %.loc10_7.2 as %D.ref;
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/index/fail_array_large_index.carbon b/toolchain/check/testdata/index/fail_array_large_index.carbon
index 18f4324de0e4..f3f8f8db882a 100644
--- a/toolchain/check/testdata/index/fail_array_large_index.carbon
+++ b/toolchain/check/testdata/index/fail_array_large_index.carbon
@@ -16,9 +16,10 @@ var a: [i32; 1] = (12,);
 // CHECK:STDERR:
 var b: i32 = a[1];
 
-// CHECK:STDERR: fail_array_large_index.carbon:[[@LINE+3]]:16: error: array index `2147483647` is past the end of type `[i32; 1]` [ArrayIndexOutOfBounds]
+// CHECK:STDERR: fail_array_large_index.carbon:[[@LINE+4]]:16: error: array index `2147483647` is past the end of type `[i32; 1]` [ArrayIndexOutOfBounds]
 // CHECK:STDERR: var c: i32 = a[0x7FFF_FFFF];
 // CHECK:STDERR:                ^~~~~~~~~~~
+// CHECK:STDERR:
 var c: i32 = a[0x7FFF_FFFF];
 
 // CHECK:STDOUT: --- fail_array_large_index.carbon
@@ -101,19 +102,19 @@ var c: i32 = a[0x7FFF_FFFF];
 // CHECK:STDOUT:   %.loc17_17.1: ref %i32 = array_index %a.ref.loc17, %.loc17_16.2 [template = <error>]
 // CHECK:STDOUT:   %.loc17_17.2: %i32 = bind_value %.loc17_17.1
 // CHECK:STDOUT:   assign file.%b.var, %.loc17_17.2
-// CHECK:STDOUT:   %a.ref.loc22: ref %array_type = name_ref a, file.%a
+// CHECK:STDOUT:   %a.ref.loc23: ref %array_type = name_ref a, file.%a
 // CHECK:STDOUT:   %int_2147483647: Core.IntLiteral = int_value 2147483647 [template = constants.%int_2147483647.d89]
-// CHECK:STDOUT:   %int_32.loc22: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:   %i32.loc22: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
-// CHECK:STDOUT:   %impl.elem0.loc22: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
-// CHECK:STDOUT:   %Convert.bound.loc22: <bound method> = bound_method %int_2147483647, %impl.elem0.loc22 [template = constants.%Convert.bound.f38]
-// CHECK:STDOUT:   %Convert.specific_fn.loc22: <specific function> = specific_function %Convert.bound.loc22, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.221]
-// CHECK:STDOUT:   %int.convert_checked.loc22: init %i32 = call %Convert.specific_fn.loc22(%int_2147483647) [template = constants.%int_2147483647.a74]
-// CHECK:STDOUT:   %.loc22_16.1: %i32 = value_of_initializer %int.convert_checked.loc22 [template = constants.%int_2147483647.a74]
-// CHECK:STDOUT:   %.loc22_16.2: %i32 = converted %int_2147483647, %.loc22_16.1 [template = constants.%int_2147483647.a74]
-// CHECK:STDOUT:   %.loc22_27.1: ref %i32 = array_index %a.ref.loc22, %.loc22_16.2 [template = <error>]
-// CHECK:STDOUT:   %.loc22_27.2: %i32 = bind_value %.loc22_27.1
-// CHECK:STDOUT:   assign file.%c.var, %.loc22_27.2
+// CHECK:STDOUT:   %int_32.loc23: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:   %i32.loc23: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:   %impl.elem0.loc23: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
+// CHECK:STDOUT:   %Convert.bound.loc23: <bound method> = bound_method %int_2147483647, %impl.elem0.loc23 [template = constants.%Convert.bound.f38]
+// CHECK:STDOUT:   %Convert.specific_fn.loc23: <specific function> = specific_function %Convert.bound.loc23, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.221]
+// CHECK:STDOUT:   %int.convert_checked.loc23: init %i32 = call %Convert.specific_fn.loc23(%int_2147483647) [template = constants.%int_2147483647.a74]
+// CHECK:STDOUT:   %.loc23_16.1: %i32 = value_of_initializer %int.convert_checked.loc23 [template = constants.%int_2147483647.a74]
+// CHECK:STDOUT:   %.loc23_16.2: %i32 = converted %int_2147483647, %.loc23_16.1 [template = constants.%int_2147483647.a74]
+// CHECK:STDOUT:   %.loc23_27.1: ref %i32 = array_index %a.ref.loc23, %.loc23_16.2 [template = <error>]
+// CHECK:STDOUT:   %.loc23_27.2: %i32 = bind_value %.loc23_27.1
+// CHECK:STDOUT:   assign file.%c.var, %.loc23_27.2
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/index/fail_array_non_int_indexing.carbon b/toolchain/check/testdata/index/fail_array_non_int_indexing.carbon
index f0723579d0a0..808be111c5f4 100644
--- a/toolchain/check/testdata/index/fail_array_non_int_indexing.carbon
+++ b/toolchain/check/testdata/index/fail_array_non_int_indexing.carbon
@@ -9,12 +9,13 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/index/fail_array_non_int_indexing.carbon
 
 var a: [i32; 1] = (12,);
-// CHECK:STDERR: fail_array_non_int_indexing.carbon:[[@LINE+6]]:16: error: cannot implicitly convert from `f64` to `i32` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_array_non_int_indexing.carbon:[[@LINE+7]]:16: error: cannot implicitly convert from `f64` to `i32` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var b: i32 = a[2.6];
 // CHECK:STDERR:                ^~~
-// CHECK:STDERR: fail_array_non_int_indexing.carbon:[[@LINE+3]]:16: note: type `f64` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]
+// CHECK:STDERR: fail_array_non_int_indexing.carbon:[[@LINE+4]]:16: note: type `f64` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]
 // CHECK:STDERR: var b: i32 = a[2.6];
 // CHECK:STDERR:                ^~~
+// CHECK:STDERR:
 var b: i32 = a[2.6];
 
 // CHECK:STDOUT: --- fail_array_non_int_indexing.carbon
@@ -79,10 +80,10 @@ var b: i32 = a[2.6];
 // CHECK:STDOUT:   %float: f64 = float_literal 2.6000000000000001 [template = constants.%float]
 // CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [template = constants.%int_32]
 // CHECK:STDOUT:   %i32: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
-// CHECK:STDOUT:   %.loc18_16: %i32 = converted %float, <error> [template = <error>]
-// CHECK:STDOUT:   %.loc18_19.1: ref %i32 = array_index %a.ref, <error> [template = <error>]
-// CHECK:STDOUT:   %.loc18_19.2: %i32 = bind_value %.loc18_19.1
-// CHECK:STDOUT:   assign file.%b.var, %.loc18_19.2
+// CHECK:STDOUT:   %.loc19_16: %i32 = converted %float, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc19_19.1: ref %i32 = array_index %a.ref, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc19_19.2: %i32 = bind_value %.loc19_19.1
+// CHECK:STDOUT:   assign file.%b.var, %.loc19_19.2
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/index/fail_array_out_of_bound_access.carbon b/toolchain/check/testdata/index/fail_array_out_of_bound_access.carbon
index 64270ca8a645..1fc58a050133 100644
--- a/toolchain/check/testdata/index/fail_array_out_of_bound_access.carbon
+++ b/toolchain/check/testdata/index/fail_array_out_of_bound_access.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/index/fail_array_out_of_bound_access.carbon
 
 var a: [i32; 1] = (12,);
-// CHECK:STDERR: fail_array_out_of_bound_access.carbon:[[@LINE+3]]:16: error: array index `1` is past the end of type `[i32; 1]` [ArrayIndexOutOfBounds]
+// CHECK:STDERR: fail_array_out_of_bound_access.carbon:[[@LINE+4]]:16: error: array index `1` is past the end of type `[i32; 1]` [ArrayIndexOutOfBounds]
 // CHECK:STDERR: var b: i32 = a[1];
 // CHECK:STDERR:                ^
+// CHECK:STDERR:
 var b: i32 = a[1];
 
 // CHECK:STDOUT: --- fail_array_out_of_bound_access.carbon
@@ -78,15 +79,15 @@ var b: i32 = a[1];
 // CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [template = constants.%int_1.5b8]
 // CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [template = constants.%int_32]
 // CHECK:STDOUT:   %i32: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
-// CHECK:STDOUT:   %impl.elem0.loc15: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
-// CHECK:STDOUT:   %Convert.bound.loc15: <bound method> = bound_method %int_1, %impl.elem0.loc15 [template = constants.%Convert.bound.ab5]
-// CHECK:STDOUT:   %Convert.specific_fn.loc15: <specific function> = specific_function %Convert.bound.loc15, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.70c]
-// CHECK:STDOUT:   %int.convert_checked.loc15: init %i32 = call %Convert.specific_fn.loc15(%int_1) [template = constants.%int_1.5d2]
-// CHECK:STDOUT:   %.loc15_16.1: %i32 = value_of_initializer %int.convert_checked.loc15 [template = constants.%int_1.5d2]
-// CHECK:STDOUT:   %.loc15_16.2: %i32 = converted %int_1, %.loc15_16.1 [template = constants.%int_1.5d2]
-// CHECK:STDOUT:   %.loc15_17.1: ref %i32 = array_index %a.ref, %.loc15_16.2 [template = <error>]
-// CHECK:STDOUT:   %.loc15_17.2: %i32 = bind_value %.loc15_17.1
-// CHECK:STDOUT:   assign file.%b.var, %.loc15_17.2
+// CHECK:STDOUT:   %impl.elem0.loc16: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
+// CHECK:STDOUT:   %Convert.bound.loc16: <bound method> = bound_method %int_1, %impl.elem0.loc16 [template = constants.%Convert.bound.ab5]
+// CHECK:STDOUT:   %Convert.specific_fn.loc16: <specific function> = specific_function %Convert.bound.loc16, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.70c]
+// CHECK:STDOUT:   %int.convert_checked.loc16: init %i32 = call %Convert.specific_fn.loc16(%int_1) [template = constants.%int_1.5d2]
+// CHECK:STDOUT:   %.loc16_16.1: %i32 = value_of_initializer %int.convert_checked.loc16 [template = constants.%int_1.5d2]
+// CHECK:STDOUT:   %.loc16_16.2: %i32 = converted %int_1, %.loc16_16.1 [template = constants.%int_1.5d2]
+// CHECK:STDOUT:   %.loc16_17.1: ref %i32 = array_index %a.ref, %.loc16_16.2 [template = <error>]
+// CHECK:STDOUT:   %.loc16_17.2: %i32 = bind_value %.loc16_17.1
+// CHECK:STDOUT:   assign file.%b.var, %.loc16_17.2
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/index/fail_expr_category.carbon b/toolchain/check/testdata/index/fail_expr_category.carbon
index 047f32ce5406..e8f89618b231 100644
--- a/toolchain/check/testdata/index/fail_expr_category.carbon
+++ b/toolchain/check/testdata/index/fail_expr_category.carbon
@@ -30,9 +30,10 @@ fn G(b: [i32; 3]) {
   // CHECK:STDERR:                  ^
   // CHECK:STDERR:
   var pf: i32* = &F()[0];
-  // CHECK:STDERR: fail_expr_category.carbon:[[@LINE+3]]:3: error: expression is not assignable [AssignmentToNonAssignable]
+  // CHECK:STDERR: fail_expr_category.carbon:[[@LINE+4]]:3: error: expression is not assignable [AssignmentToNonAssignable]
   // CHECK:STDERR:   F()[0] = 4;
   // CHECK:STDERR:   ^~~~~~
+  // CHECK:STDERR:
   F()[0] = 4;
 }
 
@@ -164,28 +165,28 @@ fn G(b: [i32; 3]) {
 // CHECK:STDOUT:   %.loc32_24.2: %i32 = bind_value %.loc32_24.1
 // CHECK:STDOUT:   %addr.loc32: %ptr.235 = addr_of <error> [template = <error>]
 // CHECK:STDOUT:   assign %pf.var, %addr.loc32
-// CHECK:STDOUT:   %F.ref.loc36: %F.type = name_ref F, file.%F.decl [template = constants.%F]
-// CHECK:STDOUT:   %.loc36_5.1: ref %array_type = temporary_storage
-// CHECK:STDOUT:   %F.call.loc36: init %array_type = call %F.ref.loc36() to %.loc36_5.1
-// CHECK:STDOUT:   %int_0.loc36: Core.IntLiteral = int_value 0 [template = constants.%int_0.5c6]
-// CHECK:STDOUT:   %.loc36_5.2: ref %array_type = temporary %.loc36_5.1, %F.call.loc36
-// CHECK:STDOUT:   %int_32.loc36: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:   %i32.loc36: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
-// CHECK:STDOUT:   %impl.elem0.loc36_7: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
-// CHECK:STDOUT:   %Convert.bound.loc36_7: <bound method> = bound_method %int_0.loc36, %impl.elem0.loc36_7 [template = constants.%Convert.bound.d04]
-// CHECK:STDOUT:   %Convert.specific_fn.loc36_7: <specific function> = specific_function %Convert.bound.loc36_7, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.d62]
-// CHECK:STDOUT:   %int.convert_checked.loc36_7: init %i32 = call %Convert.specific_fn.loc36_7(%int_0.loc36) [template = constants.%int_0.6a9]
-// CHECK:STDOUT:   %.loc36_7.1: %i32 = value_of_initializer %int.convert_checked.loc36_7 [template = constants.%int_0.6a9]
-// CHECK:STDOUT:   %.loc36_7.2: %i32 = converted %int_0.loc36, %.loc36_7.1 [template = constants.%int_0.6a9]
-// CHECK:STDOUT:   %.loc36_8.1: ref %i32 = array_index %.loc36_5.2, %.loc36_7.2
-// CHECK:STDOUT:   %.loc36_8.2: %i32 = bind_value %.loc36_8.1
-// CHECK:STDOUT:   %int_4.loc36: Core.IntLiteral = int_value 4 [template = constants.%int_4.0c1]
-// CHECK:STDOUT:   %impl.elem0.loc36_10: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
-// CHECK:STDOUT:   %Convert.bound.loc36_10: <bound method> = bound_method %int_4.loc36, %impl.elem0.loc36_10 [template = constants.%Convert.bound.ac3]
-// CHECK:STDOUT:   %Convert.specific_fn.loc36_10: <specific function> = specific_function %Convert.bound.loc36_10, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.450]
-// CHECK:STDOUT:   %int.convert_checked.loc36_10: init %i32 = call %Convert.specific_fn.loc36_10(%int_4.loc36) [template = constants.%int_4.940]
-// CHECK:STDOUT:   %.loc36_10: init %i32 = converted %int_4.loc36, %int.convert_checked.loc36_10 [template = constants.%int_4.940]
-// CHECK:STDOUT:   assign %.loc36_8.2, %.loc36_10
+// CHECK:STDOUT:   %F.ref.loc37: %F.type = name_ref F, file.%F.decl [template = constants.%F]
+// CHECK:STDOUT:   %.loc37_5.1: ref %array_type = temporary_storage
+// CHECK:STDOUT:   %F.call.loc37: init %array_type = call %F.ref.loc37() to %.loc37_5.1
+// CHECK:STDOUT:   %int_0.loc37: Core.IntLiteral = int_value 0 [template = constants.%int_0.5c6]
+// CHECK:STDOUT:   %.loc37_5.2: ref %array_type = temporary %.loc37_5.1, %F.call.loc37
+// CHECK:STDOUT:   %int_32.loc37: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:   %i32.loc37: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:   %impl.elem0.loc37_7: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
+// CHECK:STDOUT:   %Convert.bound.loc37_7: <bound method> = bound_method %int_0.loc37, %impl.elem0.loc37_7 [template = constants.%Convert.bound.d04]
+// CHECK:STDOUT:   %Convert.specific_fn.loc37_7: <specific function> = specific_function %Convert.bound.loc37_7, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.d62]
+// CHECK:STDOUT:   %int.convert_checked.loc37_7: init %i32 = call %Convert.specific_fn.loc37_7(%int_0.loc37) [template = constants.%int_0.6a9]
+// CHECK:STDOUT:   %.loc37_7.1: %i32 = value_of_initializer %int.convert_checked.loc37_7 [template = constants.%int_0.6a9]
+// CHECK:STDOUT:   %.loc37_7.2: %i32 = converted %int_0.loc37, %.loc37_7.1 [template = constants.%int_0.6a9]
+// CHECK:STDOUT:   %.loc37_8.1: ref %i32 = array_index %.loc37_5.2, %.loc37_7.2
+// CHECK:STDOUT:   %.loc37_8.2: %i32 = bind_value %.loc37_8.1
+// CHECK:STDOUT:   %int_4.loc37: Core.IntLiteral = int_value 4 [template = constants.%int_4.0c1]
+// CHECK:STDOUT:   %impl.elem0.loc37_10: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
+// CHECK:STDOUT:   %Convert.bound.loc37_10: <bound method> = bound_method %int_4.loc37, %impl.elem0.loc37_10 [template = constants.%Convert.bound.ac3]
+// CHECK:STDOUT:   %Convert.specific_fn.loc37_10: <specific function> = specific_function %Convert.bound.loc37_10, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.450]
+// CHECK:STDOUT:   %int.convert_checked.loc37_10: init %i32 = call %Convert.specific_fn.loc37_10(%int_4.loc37) [template = constants.%int_4.940]
+// CHECK:STDOUT:   %.loc37_10: init %i32 = converted %int_4.loc37, %int.convert_checked.loc37_10 [template = constants.%int_4.940]
+// CHECK:STDOUT:   assign %.loc37_8.2, %.loc37_10
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/index/fail_invalid_base.carbon b/toolchain/check/testdata/index/fail_invalid_base.carbon
index 32b9b3839b7f..3e5ca5f042f9 100644
--- a/toolchain/check/testdata/index/fail_invalid_base.carbon
+++ b/toolchain/check/testdata/index/fail_invalid_base.carbon
@@ -28,9 +28,10 @@ var b: i32 = F[1];
 // CHECK:STDERR:
 var c: i32 = {.a = 1, .b = 2}[0];
 
-// CHECK:STDERR: fail_invalid_base.carbon:[[@LINE+3]]:14: error: type `type` does not support indexing [TypeNotIndexable]
+// CHECK:STDERR: fail_invalid_base.carbon:[[@LINE+4]]:14: error: type `type` does not support indexing [TypeNotIndexable]
 // CHECK:STDERR: var d: i32 = {.a: i32, .b: i32}[0];
 // CHECK:STDERR:              ^~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 var d: i32 = {.a: i32, .b: i32}[0];
 
 // CHECK:STDOUT: --- fail_invalid_base.carbon
@@ -97,12 +98,12 @@ var d: i32 = {.a: i32, .b: i32}[0];
 // CHECK:STDOUT:   %struct: %struct_type.a.b.cfd = struct_value (%int_1.loc29, %int_2) [template = constants.%struct]
 // CHECK:STDOUT:   %.loc29_29.2: %struct_type.a.b.cfd = converted %.loc29_29.1, %struct [template = constants.%struct]
 // CHECK:STDOUT:   assign file.%c.var, <error>
-// CHECK:STDOUT:   %int_32.loc34_19: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:   %i32.loc34_19: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
-// CHECK:STDOUT:   %int_32.loc34_28: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:   %i32.loc34_28: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:   %int_32.loc35_19: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:   %i32.loc35_19: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:   %int_32.loc35_28: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:   %i32.loc35_28: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
 // CHECK:STDOUT:   %struct_type.a.b: type = struct_type {.a: %i32, .b: %i32} [template = constants.%struct_type.a.b.501]
-// CHECK:STDOUT:   %int_0.loc34: Core.IntLiteral = int_value 0 [template = constants.%int_0]
+// CHECK:STDOUT:   %int_0.loc35: Core.IntLiteral = int_value 0 [template = constants.%int_0]
 // CHECK:STDOUT:   assign file.%d.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/index/fail_name_not_found.carbon b/toolchain/check/testdata/index/fail_name_not_found.carbon
index 91da6b8a04e5..53c59cc511de 100644
--- a/toolchain/check/testdata/index/fail_name_not_found.carbon
+++ b/toolchain/check/testdata/index/fail_name_not_found.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/index/fail_name_not_found.carbon
 
 fn Main() {
-  // CHECK:STDERR: fail_name_not_found.carbon:[[@LINE+3]]:16: error: name `a` not found [NameNotFound]
+  // CHECK:STDERR: fail_name_not_found.carbon:[[@LINE+4]]:16: error: name `a` not found [NameNotFound]
   // CHECK:STDERR:   var b: i32 = a[0];
   // CHECK:STDERR:                ^
+  // CHECK:STDERR:
   var b: i32 = a[0];
 }
 
diff --git a/toolchain/check/testdata/index/fail_negative_indexing.carbon b/toolchain/check/testdata/index/fail_negative_indexing.carbon
index 26754bab164a..9f3f95e5a3dc 100644
--- a/toolchain/check/testdata/index/fail_negative_indexing.carbon
+++ b/toolchain/check/testdata/index/fail_negative_indexing.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/index/fail_negative_indexing.carbon
 
 var c: [i32; 2] = (42, 42);
-// CHECK:STDERR: fail_negative_indexing.carbon:[[@LINE+3]]:16: error: array index `-10` is past the end of type `[i32; 2]` [ArrayIndexOutOfBounds]
+// CHECK:STDERR: fail_negative_indexing.carbon:[[@LINE+4]]:16: error: array index `-10` is past the end of type `[i32; 2]` [ArrayIndexOutOfBounds]
 // CHECK:STDERR: var d: i32 = c[-10];
 // CHECK:STDERR:                ^~~
+// CHECK:STDERR:
 var d: i32 = c[-10];
 
 
@@ -95,22 +96,22 @@ var d: i32 = c[-10];
 // CHECK:STDOUT:   assign file.%c.var, %.loc11_27
 // CHECK:STDOUT:   %c.ref: ref %array_type = name_ref c, file.%c
 // CHECK:STDOUT:   %int_10: Core.IntLiteral = int_value 10 [template = constants.%int_10]
-// CHECK:STDOUT:   %impl.elem0.loc15_16.1: %Op.type.e42 = impl_witness_access constants.%impl_witness.0f6, element0 [template = constants.%Op.bba]
-// CHECK:STDOUT:   %Op.bound: <bound method> = bound_method %int_10, %impl.elem0.loc15_16.1 [template = constants.%Op.bound]
+// CHECK:STDOUT:   %impl.elem0.loc16_16.1: %Op.type.e42 = impl_witness_access constants.%impl_witness.0f6, element0 [template = constants.%Op.bba]
+// CHECK:STDOUT:   %Op.bound: <bound method> = bound_method %int_10, %impl.elem0.loc16_16.1 [template = constants.%Op.bound]
 // CHECK:STDOUT:   %int.snegate: init Core.IntLiteral = call %Op.bound(%int_10) [template = constants.%int_-10.06d]
 // CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [template = constants.%int_32]
 // CHECK:STDOUT:   %i32: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
-// CHECK:STDOUT:   %impl.elem0.loc15_16.2: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
-// CHECK:STDOUT:   %Convert.bound.loc15: <bound method> = bound_method %int.snegate, %impl.elem0.loc15_16.2 [template = constants.%Convert.bound.1ca]
-// CHECK:STDOUT:   %Convert.specific_fn.loc15: <specific function> = specific_function %Convert.bound.loc15, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.4be]
-// CHECK:STDOUT:   %.loc15_16.1: Core.IntLiteral = value_of_initializer %int.snegate [template = constants.%int_-10.06d]
-// CHECK:STDOUT:   %.loc15_16.2: Core.IntLiteral = converted %int.snegate, %.loc15_16.1 [template = constants.%int_-10.06d]
-// CHECK:STDOUT:   %int.convert_checked.loc15: init %i32 = call %Convert.specific_fn.loc15(%.loc15_16.2) [template = constants.%int_-10.c17]
-// CHECK:STDOUT:   %.loc15_16.3: %i32 = value_of_initializer %int.convert_checked.loc15 [template = constants.%int_-10.c17]
-// CHECK:STDOUT:   %.loc15_16.4: %i32 = converted %int.snegate, %.loc15_16.3 [template = constants.%int_-10.c17]
-// CHECK:STDOUT:   %.loc15_19.1: ref %i32 = array_index %c.ref, %.loc15_16.4 [template = <error>]
-// CHECK:STDOUT:   %.loc15_19.2: %i32 = bind_value %.loc15_19.1
-// CHECK:STDOUT:   assign file.%d.var, %.loc15_19.2
+// CHECK:STDOUT:   %impl.elem0.loc16_16.2: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
+// CHECK:STDOUT:   %Convert.bound.loc16: <bound method> = bound_method %int.snegate, %impl.elem0.loc16_16.2 [template = constants.%Convert.bound.1ca]
+// CHECK:STDOUT:   %Convert.specific_fn.loc16: <specific function> = specific_function %Convert.bound.loc16, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.4be]
+// CHECK:STDOUT:   %.loc16_16.1: Core.IntLiteral = value_of_initializer %int.snegate [template = constants.%int_-10.06d]
+// CHECK:STDOUT:   %.loc16_16.2: Core.IntLiteral = converted %int.snegate, %.loc16_16.1 [template = constants.%int_-10.06d]
+// CHECK:STDOUT:   %int.convert_checked.loc16: init %i32 = call %Convert.specific_fn.loc16(%.loc16_16.2) [template = constants.%int_-10.c17]
+// CHECK:STDOUT:   %.loc16_16.3: %i32 = value_of_initializer %int.convert_checked.loc16 [template = constants.%int_-10.c17]
+// CHECK:STDOUT:   %.loc16_16.4: %i32 = converted %int.snegate, %.loc16_16.3 [template = constants.%int_-10.c17]
+// CHECK:STDOUT:   %.loc16_19.1: ref %i32 = array_index %c.ref, %.loc16_16.4 [template = <error>]
+// CHECK:STDOUT:   %.loc16_19.2: %i32 = bind_value %.loc16_19.1
+// CHECK:STDOUT:   assign file.%d.var, %.loc16_19.2
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/index/fail_non_tuple_access.carbon b/toolchain/check/testdata/index/fail_non_tuple_access.carbon
index 03f502c7f074..65de4b87eefc 100644
--- a/toolchain/check/testdata/index/fail_non_tuple_access.carbon
+++ b/toolchain/check/testdata/index/fail_non_tuple_access.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/index/fail_non_tuple_access.carbon
 
 fn Main() {
-  // CHECK:STDERR: fail_non_tuple_access.carbon:[[@LINE+3]]:3: error: type `Core.IntLiteral` does not support indexing [TypeNotIndexable]
+  // CHECK:STDERR: fail_non_tuple_access.carbon:[[@LINE+4]]:3: error: type `Core.IntLiteral` does not support indexing [TypeNotIndexable]
   // CHECK:STDERR:   0[1];
   // CHECK:STDERR:   ^~~~
+  // CHECK:STDERR:
   0[1];
 }
 
diff --git a/toolchain/check/testdata/interface/fail_assoc_const_bad_default.carbon b/toolchain/check/testdata/interface/fail_assoc_const_bad_default.carbon
index e060586e23d3..398347e5b6dd 100644
--- a/toolchain/check/testdata/interface/fail_assoc_const_bad_default.carbon
+++ b/toolchain/check/testdata/interface/fail_assoc_const_bad_default.carbon
@@ -9,12 +9,13 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/fail_assoc_const_bad_default.carbon
 
 interface I {
-  // CHECK:STDERR: fail_assoc_const_bad_default.carbon:[[@LINE+6]]:3: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_assoc_const_bad_default.carbon:[[@LINE+7]]:3: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   let T:! type = 42;
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~
-  // CHECK:STDERR: fail_assoc_const_bad_default.carbon:[[@LINE+3]]:3: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR: fail_assoc_const_bad_default.carbon:[[@LINE+4]]:3: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
   // CHECK:STDERR:   let T:! type = 42;
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   let T:! type = 42;
 }
 
@@ -48,7 +49,7 @@ interface I {
 // CHECK:STDOUT: interface @I {
 // CHECK:STDOUT:   %Self: %I.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self.826]
 // CHECK:STDOUT:   %int_42: Core.IntLiteral = int_value 42 [template = constants.%int_42]
-// CHECK:STDOUT:   %.loc18: type = converted %int_42, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc19: type = converted %int_42, <error> [template = <error>]
 // CHECK:STDOUT:   %T: type = assoc_const_decl T [template]
 // CHECK:STDOUT:   %assoc0: %assoc_type = assoc_entity element0, %T [template = constants.%assoc0.790]
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interface/fail_todo_assoc_const_default.carbon b/toolchain/check/testdata/interface/fail_todo_assoc_const_default.carbon
index b84ac4975708..82c31a509ade 100644
--- a/toolchain/check/testdata/interface/fail_todo_assoc_const_default.carbon
+++ b/toolchain/check/testdata/interface/fail_todo_assoc_const_default.carbon
@@ -14,9 +14,10 @@ interface I {
   // CHECK:STDERR:   ^~~~~~~
   // CHECK:STDERR:
   default let T:! type = (i32, i32);
-  // CHECK:STDERR: fail_todo_assoc_const_default.carbon:[[@LINE+3]]:3: error: semantics TODO: `interface modifier` [SemanticsTodo]
+  // CHECK:STDERR: fail_todo_assoc_const_default.carbon:[[@LINE+4]]:3: error: semantics TODO: `interface modifier` [SemanticsTodo]
   // CHECK:STDERR:   default let N:! i32 = 42;
   // CHECK:STDERR:   ^~~~~~~
+  // CHECK:STDERR:
   default let N:! i32 = 42;
 }
 
@@ -76,8 +77,8 @@ interface I {
 // CHECK:STDOUT:   %Convert.bound: <bound method> = bound_method %int_42, %impl.elem0 [template = constants.%Convert.bound]
 // CHECK:STDOUT:   %Convert.specific_fn: <specific function> = specific_function %Convert.bound, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn]
 // CHECK:STDOUT:   %int.convert_checked: init %i32 = call %Convert.specific_fn(%int_42) [template = constants.%int_42.c68]
-// CHECK:STDOUT:   %.loc20_27.1: %i32 = value_of_initializer %int.convert_checked [template = constants.%int_42.c68]
-// CHECK:STDOUT:   %.loc20_27.2: %i32 = converted %int_42, %.loc20_27.1 [template = constants.%int_42.c68]
+// CHECK:STDOUT:   %.loc21_27.1: %i32 = value_of_initializer %int.convert_checked [template = constants.%int_42.c68]
+// CHECK:STDOUT:   %.loc21_27.2: %i32 = converted %int_42, %.loc21_27.1 [template = constants.%int_42.c68]
 // CHECK:STDOUT:   %N: %i32 = assoc_const_decl N [template]
 // CHECK:STDOUT:   %assoc1: %assoc_type.4fb = assoc_entity element1, %N [template = constants.%assoc1]
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interface/fail_todo_define_default_fn_inline.carbon b/toolchain/check/testdata/interface/fail_todo_define_default_fn_inline.carbon
index c491ec7ad4db..7848c1cc0125 100644
--- a/toolchain/check/testdata/interface/fail_todo_define_default_fn_inline.carbon
+++ b/toolchain/check/testdata/interface/fail_todo_define_default_fn_inline.carbon
@@ -15,9 +15,10 @@ interface Interface {
   // CHECK:STDERR:
   default fn F() {}
 
-  // CHECK:STDERR: fail_todo_define_default_fn_inline.carbon:[[@LINE+3]]:3: error: semantics TODO: `interface modifier` [SemanticsTodo]
+  // CHECK:STDERR: fail_todo_define_default_fn_inline.carbon:[[@LINE+4]]:3: error: semantics TODO: `interface modifier` [SemanticsTodo]
   // CHECK:STDERR:   default fn G(a: i32, b: i32) -> i32 = "int.sadd";
   // CHECK:STDERR:   ^~~~~~~
+  // CHECK:STDERR:
   default fn G(a: i32, b: i32) -> i32 = "int.sadd";
 }
 
@@ -67,18 +68,18 @@ interface Interface {
 // CHECK:STDOUT:     %return.patt: %i32 = return_slot_pattern
 // CHECK:STDOUT:     %return.param_patt: %i32 = out_param_pattern %return.patt, runtime_param2
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %int_32.loc21_35: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:     %i32.loc21_35: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:     %int_32.loc22_35: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:     %i32.loc22_35: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
 // CHECK:STDOUT:     %a.param: %i32 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc21_19: type = splice_block %i32.loc21_19 [template = constants.%i32] {
-// CHECK:STDOUT:       %int_32.loc21_19: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:       %i32.loc21_19: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:     %.loc22_19: type = splice_block %i32.loc22_19 [template = constants.%i32] {
+// CHECK:STDOUT:       %int_32.loc22_19: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:       %i32.loc22_19: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: %i32 = bind_name a, %a.param
 // CHECK:STDOUT:     %b.param: %i32 = value_param runtime_param1
-// CHECK:STDOUT:     %.loc21_27: type = splice_block %i32.loc21_27 [template = constants.%i32] {
-// CHECK:STDOUT:       %int_32.loc21_27: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:       %i32.loc21_27: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:     %.loc22_27: type = splice_block %i32.loc22_27 [template = constants.%i32] {
+// CHECK:STDOUT:       %int_32.loc22_27: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:       %i32.loc22_27: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %b: %i32 = bind_name b, %b.param
 // CHECK:STDOUT:     %return.param: ref %i32 = out_param runtime_param2
diff --git a/toolchain/check/testdata/interface/fail_todo_define_default_fn_out_of_line.carbon b/toolchain/check/testdata/interface/fail_todo_define_default_fn_out_of_line.carbon
index e2500b65e35d..c8c608ccf8ef 100644
--- a/toolchain/check/testdata/interface/fail_todo_define_default_fn_out_of_line.carbon
+++ b/toolchain/check/testdata/interface/fail_todo_define_default_fn_out_of_line.carbon
@@ -33,12 +33,13 @@ interface Interface {
 // CHECK:STDERR:
 fn Interface.F() {}
 
-// CHECK:STDERR: fail_todo_define_default_fn_out_of_line.carbon:[[@LINE+6]]:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
+// CHECK:STDERR: fail_todo_define_default_fn_out_of_line.carbon:[[@LINE+7]]:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
 // CHECK:STDERR: fn Interface.G(a: i32, b: i32) -> i32 = "int.sadd";
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_todo_define_default_fn_out_of_line.carbon:[[@LINE-15]]:3: note: name is previously declared here [NameDeclPrevious]
 // CHECK:STDERR:   default fn G(a: i32, b: i32) -> i32;
 // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 fn Interface.G(a: i32, b: i32) -> i32 = "int.sadd";
 
 // --- dependent_return_type.carbon
@@ -100,7 +101,7 @@ fn Interface.C.F[self: Self](U:! type, u: U) -> U { return u; }
 // CHECK:STDOUT:   %Core.import = import Core
 // CHECK:STDOUT:   %Interface.decl: type = interface_decl @Interface [template = constants.%Interface.type] {} {}
 // CHECK:STDOUT:   %.decl.loc23: %.type.136624.1 = fn_decl @.1 [template = constants.%.563abc.1] {} {}
-// CHECK:STDOUT:   %.decl.loc31: %.type.136624.2 = fn_decl @.2 [template = constants.%.563abc.2] {
+// CHECK:STDOUT:   %.decl.loc32: %.type.136624.2 = fn_decl @.2 [template = constants.%.563abc.2] {
 // CHECK:STDOUT:     %a.patt: %i32 = binding_pattern a
 // CHECK:STDOUT:     %a.param_patt: %i32 = value_param_pattern %a.patt, runtime_param0
 // CHECK:STDOUT:     %b.patt: %i32 = binding_pattern b
@@ -108,18 +109,18 @@ fn Interface.C.F[self: Self](U:! type, u: U) -> U { return u; }
 // CHECK:STDOUT:     %return.patt: %i32 = return_slot_pattern
 // CHECK:STDOUT:     %return.param_patt: %i32 = out_param_pattern %return.patt, runtime_param2
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %int_32.loc31_35: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:     %i32.loc31_35: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:     %int_32.loc32_35: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:     %i32.loc32_35: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
 // CHECK:STDOUT:     %a.param: %i32 = value_param runtime_param0
-// CHECK:STDOUT:     %.loc31_19: type = splice_block %i32.loc31_19 [template = constants.%i32] {
-// CHECK:STDOUT:       %int_32.loc31_19: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:       %i32.loc31_19: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:     %.loc32_19: type = splice_block %i32.loc32_19 [template = constants.%i32] {
+// CHECK:STDOUT:       %int_32.loc32_19: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:       %i32.loc32_19: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %a: %i32 = bind_name a, %a.param
 // CHECK:STDOUT:     %b.param: %i32 = value_param runtime_param1
-// CHECK:STDOUT:     %.loc31_27: type = splice_block %i32.loc31_27 [template = constants.%i32] {
-// CHECK:STDOUT:       %int_32.loc31_27: Core.IntLiteral = int_value 32 [template = constants.%int_32]
-// CHECK:STDOUT:       %i32.loc31_27: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
+// CHECK:STDOUT:     %.loc32_27: type = splice_block %i32.loc32_27 [template = constants.%i32] {
+// CHECK:STDOUT:       %int_32.loc32_27: Core.IntLiteral = int_value 32 [template = constants.%int_32]
+// CHECK:STDOUT:       %i32.loc32_27: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:     %b: %i32 = bind_name b, %b.param
 // CHECK:STDOUT:     %return.param: ref %i32 = out_param runtime_param2
diff --git a/toolchain/check/testdata/interface/member_lookup.carbon b/toolchain/check/testdata/interface/member_lookup.carbon
index a239317c1eb4..7c7a57d9a8a2 100644
--- a/toolchain/check/testdata/interface/member_lookup.carbon
+++ b/toolchain/check/testdata/interface/member_lookup.carbon
@@ -41,9 +41,10 @@ fn AccessMissingGeneric[T:! type](I:! Interface(T)) -> T {
 }
 
 fn AccessMissingConcrete(I:! Interface(i32)) -> i32 {
-  // CHECK:STDERR: fail_no_member.carbon:[[@LINE+3]]:10: error: member name `nonesuch` not found in `Interface(i32)` [MemberNameNotFoundInScope]
+  // CHECK:STDERR: fail_no_member.carbon:[[@LINE+4]]:10: error: member name `nonesuch` not found in `Interface(i32)` [MemberNameNotFoundInScope]
   // CHECK:STDERR:   return I.nonesuch;
   // CHECK:STDERR:          ^~~~~~~~~~
+  // CHECK:STDERR:
   return I.nonesuch;
 }
 
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_add_member_outside_definition.carbon b/toolchain/check/testdata/interface/no_prelude/fail_add_member_outside_definition.carbon
index 1be6348f5b77..719ac3e89f8b 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_add_member_outside_definition.carbon
+++ b/toolchain/check/testdata/interface/no_prelude/fail_add_member_outside_definition.carbon
@@ -25,9 +25,10 @@ interface Outer {
     // CHECK:STDERR:
     fn Outer.F();
   }
-  // CHECK:STDERR: fail_add_member_outside_definition.carbon:[[@LINE+3]]:12: error: out-of-line declaration requires a declaration in scoped entity [QualifiedDeclOutsideScopeEntity]
+  // CHECK:STDERR: fail_add_member_outside_definition.carbon:[[@LINE+4]]:12: error: out-of-line declaration requires a declaration in scoped entity [QualifiedDeclOutsideScopeEntity]
   // CHECK:STDERR:   fn Inner.F();
   // CHECK:STDERR:            ^
+  // CHECK:STDERR:
   fn Inner.F();
 }
 
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_assoc_const_not_binding.carbon b/toolchain/check/testdata/interface/no_prelude/fail_assoc_const_not_binding.carbon
index 1667a902d502..fd13758d8057 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_assoc_const_not_binding.carbon
+++ b/toolchain/check/testdata/interface/no_prelude/fail_assoc_const_not_binding.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/fail_assoc_const_not_binding.carbon
 
 interface I {
-  // CHECK:STDERR: fail_assoc_const_not_binding.carbon:[[@LINE+3]]:3: error: semantics TODO: `tuple pattern in let/var` [SemanticsTodo]
+  // CHECK:STDERR: fail_assoc_const_not_binding.carbon:[[@LINE+4]]:3: error: semantics TODO: `tuple pattern in let/var` [SemanticsTodo]
   // CHECK:STDERR:   let (T:! type, U:! type);
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   let (T:! type, U:! type);
 }
 
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_assoc_const_not_constant.carbon b/toolchain/check/testdata/interface/no_prelude/fail_assoc_const_not_constant.carbon
index 30f3ed7a5e2b..2e45b27a0801 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_assoc_const_not_constant.carbon
+++ b/toolchain/check/testdata/interface/no_prelude/fail_assoc_const_not_constant.carbon
@@ -9,13 +9,14 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/fail_assoc_const_not_constant.carbon
 
 interface I {
-  // CHECK:STDERR: fail_assoc_const_not_constant.carbon:[[@LINE+7]]:10: error: `Core.Int` implicitly referenced here, but package `Core` not found [CoreNotFound]
+  // CHECK:STDERR: fail_assoc_const_not_constant.carbon:[[@LINE+8]]:10: error: `Core.Int` implicitly referenced here, but package `Core` not found [CoreNotFound]
   // CHECK:STDERR:   let a: i32;
   // CHECK:STDERR:          ^~~
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_assoc_const_not_constant.carbon:[[@LINE+3]]:7: error: pattern in associated constant declaration must be a single `:!` binding [ExpectedSymbolicBindingInAssociatedConstant]
+  // CHECK:STDERR: fail_assoc_const_not_constant.carbon:[[@LINE+4]]:7: error: pattern in associated constant declaration must be a single `:!` binding [ExpectedSymbolicBindingInAssociatedConstant]
   // CHECK:STDERR:   let a: i32;
   // CHECK:STDERR:       ^
+  // CHECK:STDERR:
   let a: i32;
 }
 
@@ -39,10 +40,10 @@ alias UseOther = I.other;
 // CHECK:STDOUT:     .UseOther = %UseOther
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %I.decl: type = interface_decl @I [template = constants.%I.type] {} {}
-// CHECK:STDOUT:   %I.ref.loc23: type = name_ref I, %I.decl [template = constants.%I.type]
+// CHECK:STDOUT:   %I.ref.loc24: type = name_ref I, %I.decl [template = constants.%I.type]
 // CHECK:STDOUT:   %a.ref: <error> = name_ref a, <error> [template = <error>]
 // CHECK:STDOUT:   %UseA: <error> = bind_alias UseA, <error> [template = <error>]
-// CHECK:STDOUT:   %I.ref.loc26: type = name_ref I, %I.decl [template = constants.%I.type]
+// CHECK:STDOUT:   %I.ref.loc27: type = name_ref I, %I.decl [template = constants.%I.type]
 // CHECK:STDOUT:   %other.ref: <error> = name_ref other, <error> [template = <error>]
 // CHECK:STDOUT:   %UseOther: <error> = bind_alias UseOther, <error> [template = <error>]
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_assoc_const_template.carbon b/toolchain/check/testdata/interface/no_prelude/fail_assoc_const_template.carbon
index 1cd44210feb9..b6a222e8fac9 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_assoc_const_template.carbon
+++ b/toolchain/check/testdata/interface/no_prelude/fail_assoc_const_template.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/fail_assoc_const_template.carbon
 
 interface I {
-  // CHECK:STDERR: fail_assoc_const_template.carbon:[[@LINE+3]]:7: error: semantics TODO: `HandleTemplate` [SemanticsTodo]
+  // CHECK:STDERR: fail_assoc_const_template.carbon:[[@LINE+4]]:7: error: semantics TODO: `HandleTemplate` [SemanticsTodo]
   // CHECK:STDERR:   let template T:! type;
   // CHECK:STDERR:       ^~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   let template T:! type;
 }
 
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_definition_imported.carbon b/toolchain/check/testdata/interface/no_prelude/fail_definition_imported.carbon
index 9bb021a516f1..9b072163dd65 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_definition_imported.carbon
+++ b/toolchain/check/testdata/interface/no_prelude/fail_definition_imported.carbon
@@ -19,13 +19,14 @@ interface I;
 library "[[@TEST_NAME]]";
 import library "a";
 
-// CHECK:STDERR: fail_b.carbon:[[@LINE+7]]:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
+// CHECK:STDERR: fail_b.carbon:[[@LINE+8]]:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
 // CHECK:STDERR: interface I {}
 // CHECK:STDERR: ^~~~~~~~~~~~~
 // CHECK:STDERR: fail_b.carbon:[[@LINE-5]]:1: in import [InImport]
 // CHECK:STDERR: a.carbon:4:1: note: name is previously declared here [NameDeclPrevious]
 // CHECK:STDERR: interface I;
 // CHECK:STDERR: ^~~~~~~~~~~~
+// CHECK:STDERR:
 interface I {}
 
 // CHECK:STDOUT: --- a.carbon
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_duplicate.carbon b/toolchain/check/testdata/interface/no_prelude/fail_duplicate.carbon
index e5a11e438abe..befc87f9b1ab 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_duplicate.carbon
+++ b/toolchain/check/testdata/interface/no_prelude/fail_duplicate.carbon
@@ -61,12 +61,13 @@ interface Function;
 
 class Class;
 
-// CHECK:STDERR: fail_name_conflict_with_class.carbon:[[@LINE+6]]:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
+// CHECK:STDERR: fail_name_conflict_with_class.carbon:[[@LINE+7]]:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
 // CHECK:STDERR: interface Class { }
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_name_conflict_with_class.carbon:[[@LINE-5]]:1: note: name is previously declared here [NameDeclPrevious]
 // CHECK:STDERR: class Class;
 // CHECK:STDERR: ^~~~~~~~~~~~
+// CHECK:STDERR:
 interface Class { }
 
 // CHECK:STDOUT: --- fail_redefine_without_dependents.carbon
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_generic_redeclaration.carbon b/toolchain/check/testdata/interface/no_prelude/fail_generic_redeclaration.carbon
index 3788048d439c..38c16725e766 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_generic_redeclaration.carbon
+++ b/toolchain/check/testdata/interface/no_prelude/fail_generic_redeclaration.carbon
@@ -29,12 +29,13 @@ interface Generic(T:! type);
 interface Generic {}
 
 interface DifferentParams(T:! type);
-// CHECK:STDERR: fail_generic_redeclaration.carbon:[[@LINE+6]]:27: error: type `()` of parameter 1 in redeclaration differs from previous parameter type `type` [RedeclParamDiffersType]
+// CHECK:STDERR: fail_generic_redeclaration.carbon:[[@LINE+7]]:27: error: type `()` of parameter 1 in redeclaration differs from previous parameter type `type` [RedeclParamDiffersType]
 // CHECK:STDERR: interface DifferentParams(T:! ()) {}
 // CHECK:STDERR:                           ^~~~~~
 // CHECK:STDERR: fail_generic_redeclaration.carbon:[[@LINE-4]]:27: note: previous declaration's corresponding parameter here [RedeclParamPrevious]
 // CHECK:STDERR: interface DifferentParams(T:! type);
 // CHECK:STDERR:                           ^~~~~~~~
+// CHECK:STDERR:
 interface DifferentParams(T:! ()) {}
 
 // CHECK:STDOUT: --- fail_generic_redeclaration.carbon
@@ -91,16 +92,16 @@ interface DifferentParams(T:! ()) {}
 // CHECK:STDOUT:     %T.param: type = value_param runtime_param<invalid>
 // CHECK:STDOUT:     %T.loc31_27.1: type = bind_symbolic_name T, 0, %T.param [symbolic = %T.loc31_27.2 (constants.%T.8b3)]
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %.decl.loc38: %.type.abf52e.2 = interface_decl @.3 [template = constants.%.generic.0a9e18.2] {
-// CHECK:STDOUT:     %T.patt.loc38_27.1: %empty_tuple.type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc38_27.2 (constants.%T.patt.e60)]
-// CHECK:STDOUT:     %T.param_patt: %empty_tuple.type = value_param_pattern %T.patt.loc38_27.1, runtime_param<invalid> [symbolic = %T.patt.loc38_27.2 (constants.%T.patt.e60)]
+// CHECK:STDOUT:   %.decl.loc39: %.type.abf52e.2 = interface_decl @.3 [template = constants.%.generic.0a9e18.2] {
+// CHECK:STDOUT:     %T.patt.loc39_27.1: %empty_tuple.type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc39_27.2 (constants.%T.patt.e60)]
+// CHECK:STDOUT:     %T.param_patt: %empty_tuple.type = value_param_pattern %T.patt.loc39_27.1, runtime_param<invalid> [symbolic = %T.patt.loc39_27.2 (constants.%T.patt.e60)]
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %T.param: %empty_tuple.type = value_param runtime_param<invalid>
-// CHECK:STDOUT:     %.loc38_32.1: type = splice_block %.loc38_32.3 [template = constants.%empty_tuple.type] {
-// CHECK:STDOUT:       %.loc38_32.2: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:       %.loc38_32.3: type = converted %.loc38_32.2, constants.%empty_tuple.type [template = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %.loc39_32.1: type = splice_block %.loc39_32.3 [template = constants.%empty_tuple.type] {
+// CHECK:STDOUT:       %.loc39_32.2: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:       %.loc39_32.3: type = converted %.loc39_32.2, constants.%empty_tuple.type [template = constants.%empty_tuple.type]
 // CHECK:STDOUT:     }
-// CHECK:STDOUT:     %T.loc38_27.1: %empty_tuple.type = bind_symbolic_name T, 0, %T.param [symbolic = %T.loc38_27.2 (constants.%T.7a6)]
+// CHECK:STDOUT:     %T.loc39_27.1: %empty_tuple.type = bind_symbolic_name T, 0, %T.param [symbolic = %T.loc39_27.2 (constants.%T.7a6)]
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -145,12 +146,12 @@ interface DifferentParams(T:! ()) {}
 // CHECK:STDOUT:   interface;
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: generic interface @.3(%T.loc38_27.1: %empty_tuple.type) {
-// CHECK:STDOUT:   %T.loc38_27.2: %empty_tuple.type = bind_symbolic_name T, 0 [symbolic = %T.loc38_27.2 (constants.%T.7a6)]
-// CHECK:STDOUT:   %T.patt.loc38_27.2: %empty_tuple.type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc38_27.2 (constants.%T.patt.e60)]
+// CHECK:STDOUT: generic interface @.3(%T.loc39_27.1: %empty_tuple.type) {
+// CHECK:STDOUT:   %T.loc39_27.2: %empty_tuple.type = bind_symbolic_name T, 0 [symbolic = %T.loc39_27.2 (constants.%T.7a6)]
+// CHECK:STDOUT:   %T.patt.loc39_27.2: %empty_tuple.type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc39_27.2 (constants.%T.patt.e60)]
 // CHECK:STDOUT:
 // CHECK:STDOUT: !definition:
-// CHECK:STDOUT:   %.type: type = facet_type <@.3, @.3(%T.loc38_27.2)> [symbolic = %.type (constants.%.type.b4a)]
+// CHECK:STDOUT:   %.type: type = facet_type <@.3, @.3(%T.loc39_27.2)> [symbolic = %.type (constants.%.type.b4a)]
 // CHECK:STDOUT:   %Self.2: %.type.b4a = bind_symbolic_name Self, 1 [symbolic = %Self.2 (constants.%Self.bb6)]
 // CHECK:STDOUT:
 // CHECK:STDOUT:   interface {
@@ -180,9 +181,9 @@ interface DifferentParams(T:! ()) {}
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @.3(constants.%T.7a6) {
-// CHECK:STDOUT:   %T.loc38_27.2 => constants.%T.7a6
-// CHECK:STDOUT:   %T.patt.loc38_27.2 => constants.%T.7a6
+// CHECK:STDOUT:   %T.loc39_27.2 => constants.%T.7a6
+// CHECK:STDOUT:   %T.patt.loc39_27.2 => constants.%T.7a6
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: specific @.3(%T.loc38_27.2) {}
+// CHECK:STDOUT: specific @.3(%T.loc39_27.2) {}
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_lookup_in_type_type.carbon b/toolchain/check/testdata/interface/no_prelude/fail_lookup_in_type_type.carbon
index 1f6aaadc8159..c77a171db057 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_lookup_in_type_type.carbon
+++ b/toolchain/check/testdata/interface/no_prelude/fail_lookup_in_type_type.carbon
@@ -22,9 +22,10 @@ let T: type.not_found = {};
 
 library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_lookup_type_where.carbon:[[@LINE+3]]:8: error: member name `missing` not found [MemberNameNotFound]
+// CHECK:STDERR: fail_lookup_type_where.carbon:[[@LINE+4]]:8: error: member name `missing` not found [MemberNameNotFound]
 // CHECK:STDERR: let U: (type where .Self impls type).missing = {};
 // CHECK:STDERR:        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 let U: (type where .Self impls type).missing = {};
 
 // CHECK:STDOUT: --- fail_lookup_in_type.carbon
@@ -60,7 +61,7 @@ let U: (type where .Self impls type).missing = {};
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %.loc7: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %.loc8: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:   %U: <error> = bind_name U, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_lookup_undefined.carbon b/toolchain/check/testdata/interface/no_prelude/fail_lookup_undefined.carbon
index 32576c0de209..82c7c9ef56b2 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_lookup_undefined.carbon
+++ b/toolchain/check/testdata/interface/no_prelude/fail_lookup_undefined.carbon
@@ -43,9 +43,10 @@ interface BeingDefined {
   // CHECK:STDERR:             ^~~~~~~~~~~~~~
   // CHECK:STDERR:
   fn H() -> BeingDefined.T;
-  // CHECK:STDERR: fail_lookup_undefined.carbon:[[@LINE+3]]:6: error: name `BeingDefined` not found [NameNotFound]
+  // CHECK:STDERR: fail_lookup_undefined.carbon:[[@LINE+4]]:6: error: name `BeingDefined` not found [NameNotFound]
   // CHECK:STDERR:   fn BeingDefined.I();
   // CHECK:STDERR:      ^~~~~~~~~~~~
+  // CHECK:STDERR:
   fn BeingDefined.I();
 }
 
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_member_lookup.carbon b/toolchain/check/testdata/interface/no_prelude/fail_member_lookup.carbon
index b9121df6a3c5..38852fc34569 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_member_lookup.carbon
+++ b/toolchain/check/testdata/interface/no_prelude/fail_member_lookup.carbon
@@ -30,9 +30,10 @@ fn F() {
 
 interface Different {}
 
-// CHECK:STDERR: fail_member_lookup.carbon:[[@LINE+3]]:24: error: cannot access member of interface `Interface` in type `Different` that does not implement that interface [MissingImplInMemberAccess]
+// CHECK:STDERR: fail_member_lookup.carbon:[[@LINE+4]]:24: error: cannot access member of interface `Interface` in type `Different` that does not implement that interface [MissingImplInMemberAccess]
 // CHECK:STDERR: fn G(U:! Different) -> U.(Interface.T);
 // CHECK:STDERR:                        ^~~~~~~~~~~~~~~
+// CHECK:STDERR:
 fn G(U:! Different) -> U.(Interface.T);
 
 // CHECK:STDOUT: --- fail_member_lookup.carbon
@@ -67,17 +68,17 @@ fn G(U:! Different) -> U.(Interface.T);
 // CHECK:STDOUT:   %F.decl: %F.type.b25 = fn_decl @F.2 [template = constants.%F.c41] {} {}
 // CHECK:STDOUT:   %Different.decl: type = interface_decl @Different [template = constants.%Different.type] {} {}
 // CHECK:STDOUT:   %G.decl: %G.type = fn_decl @G [template = constants.%G] {
-// CHECK:STDOUT:     %U.patt.loc36_6.1: %Different.type = symbolic_binding_pattern U, 0 [symbolic = %U.patt.loc36_6.2 (constants.%U.patt)]
-// CHECK:STDOUT:     %U.param_patt: %Different.type = value_param_pattern %U.patt.loc36_6.1, runtime_param<invalid> [symbolic = %U.patt.loc36_6.2 (constants.%U.patt)]
+// CHECK:STDOUT:     %U.patt.loc37_6.1: %Different.type = symbolic_binding_pattern U, 0 [symbolic = %U.patt.loc37_6.2 (constants.%U.patt)]
+// CHECK:STDOUT:     %U.param_patt: %Different.type = value_param_pattern %U.patt.loc37_6.1, runtime_param<invalid> [symbolic = %U.patt.loc37_6.2 (constants.%U.patt)]
 // CHECK:STDOUT:     %return.patt: <error> = return_slot_pattern
 // CHECK:STDOUT:     %return.param_patt: <error> = out_param_pattern %return.patt, runtime_param0
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %U.ref: %Different.type = name_ref U, %U.loc36_6.1 [symbolic = %U.loc36_6.2 (constants.%U)]
+// CHECK:STDOUT:     %U.ref: %Different.type = name_ref U, %U.loc37_6.1 [symbolic = %U.loc37_6.2 (constants.%U)]
 // CHECK:STDOUT:     %Interface.ref: type = name_ref Interface, file.%Interface.decl [template = constants.%Interface.type]
 // CHECK:STDOUT:     %T.ref: %assoc_type = name_ref T, @Interface.%assoc1 [template = constants.%assoc1]
 // CHECK:STDOUT:     %U.param: %Different.type = value_param runtime_param<invalid>
 // CHECK:STDOUT:     %Different.ref: type = name_ref Different, file.%Different.decl [template = constants.%Different.type]
-// CHECK:STDOUT:     %U.loc36_6.1: %Different.type = bind_symbolic_name U, 0, %U.param [symbolic = %U.loc36_6.2 (constants.%U)]
+// CHECK:STDOUT:     %U.loc37_6.1: %Different.type = bind_symbolic_name U, 0, %U.param [symbolic = %U.loc37_6.2 (constants.%U)]
 // CHECK:STDOUT:     %return.param: ref <error> = out_param runtime_param0
 // CHECK:STDOUT:     %return: ref <error> = return_slot %return.param
 // CHECK:STDOUT:   }
@@ -119,9 +120,9 @@ fn G(U:! Different) -> U.(Interface.T);
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: generic fn @G(%U.loc36_6.1: %Different.type) {
-// CHECK:STDOUT:   %U.loc36_6.2: %Different.type = bind_symbolic_name U, 0 [symbolic = %U.loc36_6.2 (constants.%U)]
-// CHECK:STDOUT:   %U.patt.loc36_6.2: %Different.type = symbolic_binding_pattern U, 0 [symbolic = %U.patt.loc36_6.2 (constants.%U.patt)]
+// CHECK:STDOUT: generic fn @G(%U.loc37_6.1: %Different.type) {
+// CHECK:STDOUT:   %U.loc37_6.2: %Different.type = bind_symbolic_name U, 0 [symbolic = %U.loc37_6.2 (constants.%U)]
+// CHECK:STDOUT:   %U.patt.loc37_6.2: %Different.type = symbolic_binding_pattern U, 0 [symbolic = %U.patt.loc37_6.2 (constants.%U.patt)]
 // CHECK:STDOUT:
 // CHECK:STDOUT:   fn(%U.param_patt: %Different.type) -> <error>;
 // CHECK:STDOUT: }
@@ -129,7 +130,7 @@ fn G(U:! Different) -> U.(Interface.T);
 // CHECK:STDOUT: specific @F.1(constants.%Self.719) {}
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @G(constants.%U) {
-// CHECK:STDOUT:   %U.loc36_6.2 => constants.%U
-// CHECK:STDOUT:   %U.patt.loc36_6.2 => constants.%U
+// CHECK:STDOUT:   %U.loc37_6.2 => constants.%U
+// CHECK:STDOUT:   %U.patt.loc37_6.2 => constants.%U
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_modifiers.carbon b/toolchain/check/testdata/interface/no_prelude/fail_modifiers.carbon
index f115b08dd809..d7a268d10c84 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_modifiers.carbon
+++ b/toolchain/check/testdata/interface/no_prelude/fail_modifiers.carbon
@@ -67,9 +67,10 @@ interface I {
 library "[[@TEST_NAME]]";
 
 interface I {
-  // CHECK:STDERR: fail_protected_member.carbon:[[@LINE+3]]:3: error: `protected` not allowed; requires class scope [ModifierProtectedNotAllowed]
+  // CHECK:STDERR: fail_protected_member.carbon:[[@LINE+4]]:3: error: `protected` not allowed; requires class scope [ModifierProtectedNotAllowed]
   // CHECK:STDERR:   protected fn F[self: Self]();
   // CHECK:STDERR:   ^~~~~~~~~
+  // CHECK:STDERR:
   protected fn F[self: Self]();
 }
 
@@ -222,16 +223,16 @@ interface I {
 // CHECK:STDOUT: interface @I {
 // CHECK:STDOUT:   %Self: %I.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
 // CHECK:STDOUT:   %F.decl: %F.type = fn_decl @F [template = constants.%F] {
-// CHECK:STDOUT:     %self.patt: @F.%Self.as_type.loc8_24.1 (%Self.as_type) = binding_pattern self
-// CHECK:STDOUT:     %self.param_patt: @F.%Self.as_type.loc8_24.1 (%Self.as_type) = value_param_pattern %self.patt, runtime_param0
+// CHECK:STDOUT:     %self.patt: @F.%Self.as_type.loc9_24.1 (%Self.as_type) = binding_pattern self
+// CHECK:STDOUT:     %self.param_patt: @F.%Self.as_type.loc9_24.1 (%Self.as_type) = value_param_pattern %self.patt, runtime_param0
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %self.param: @F.%Self.as_type.loc8_24.1 (%Self.as_type) = value_param runtime_param0
-// CHECK:STDOUT:     %.loc8_24.1: type = splice_block %.loc8_24.2 [symbolic = %Self.as_type.loc8_24.1 (constants.%Self.as_type)] {
+// CHECK:STDOUT:     %self.param: @F.%Self.as_type.loc9_24.1 (%Self.as_type) = value_param runtime_param0
+// CHECK:STDOUT:     %.loc9_24.1: type = splice_block %.loc9_24.2 [symbolic = %Self.as_type.loc9_24.1 (constants.%Self.as_type)] {
 // CHECK:STDOUT:       %Self.ref: %I.type = name_ref Self, @I.%Self [symbolic = %Self (constants.%Self)]
-// CHECK:STDOUT:       %Self.as_type.loc8_24.2: type = facet_access_type %Self.ref [symbolic = %Self.as_type.loc8_24.1 (constants.%Self.as_type)]
-// CHECK:STDOUT:       %.loc8_24.2: type = converted %Self.ref, %Self.as_type.loc8_24.2 [symbolic = %Self.as_type.loc8_24.1 (constants.%Self.as_type)]
+// CHECK:STDOUT:       %Self.as_type.loc9_24.2: type = facet_access_type %Self.ref [symbolic = %Self.as_type.loc9_24.1 (constants.%Self.as_type)]
+// CHECK:STDOUT:       %.loc9_24.2: type = converted %Self.ref, %Self.as_type.loc9_24.2 [symbolic = %Self.as_type.loc9_24.1 (constants.%Self.as_type)]
 // CHECK:STDOUT:     }
-// CHECK:STDOUT:     %self: @F.%Self.as_type.loc8_24.1 (%Self.as_type) = bind_name self, %self.param
+// CHECK:STDOUT:     %self: @F.%Self.as_type.loc9_24.1 (%Self.as_type) = bind_name self, %self.param
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %assoc0: %F.assoc_type = assoc_entity element0, %F.decl [template = constants.%assoc0]
 // CHECK:STDOUT:
@@ -243,13 +244,13 @@ interface I {
 // CHECK:STDOUT:
 // CHECK:STDOUT: generic fn @F(@I.%Self: %I.type) {
 // CHECK:STDOUT:   %Self: %I.type = bind_symbolic_name Self, 0 [symbolic = %Self (constants.%Self)]
-// CHECK:STDOUT:   %Self.as_type.loc8_24.1: type = facet_access_type %Self [symbolic = %Self.as_type.loc8_24.1 (constants.%Self.as_type)]
+// CHECK:STDOUT:   %Self.as_type.loc9_24.1: type = facet_access_type %Self [symbolic = %Self.as_type.loc9_24.1 (constants.%Self.as_type)]
 // CHECK:STDOUT:
-// CHECK:STDOUT:   fn[%self.param_patt: @F.%Self.as_type.loc8_24.1 (%Self.as_type)]();
+// CHECK:STDOUT:   fn[%self.param_patt: @F.%Self.as_type.loc9_24.1 (%Self.as_type)]();
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @F(constants.%Self) {
 // CHECK:STDOUT:   %Self => constants.%Self
-// CHECK:STDOUT:   %Self.as_type.loc8_24.1 => constants.%Self.as_type
+// CHECK:STDOUT:   %Self.as_type.loc9_24.1 => constants.%Self.as_type
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_redeclare_member.carbon b/toolchain/check/testdata/interface/no_prelude/fail_redeclare_member.carbon
index 6fd07ce7429d..b9f5ce547f9e 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_redeclare_member.carbon
+++ b/toolchain/check/testdata/interface/no_prelude/fail_redeclare_member.carbon
@@ -10,12 +10,13 @@
 
 interface Interface {
   fn F();
-  // CHECK:STDERR: fail_redeclare_member.carbon:[[@LINE+6]]:3: error: duplicate name being declared in the same scope [NameDeclDuplicate]
+  // CHECK:STDERR: fail_redeclare_member.carbon:[[@LINE+7]]:3: error: duplicate name being declared in the same scope [NameDeclDuplicate]
   // CHECK:STDERR:   fn F();
   // CHECK:STDERR:   ^~~~~~~
   // CHECK:STDERR: fail_redeclare_member.carbon:[[@LINE-4]]:3: note: name is previously declared here [NameDeclPrevious]
   // CHECK:STDERR:   fn F();
   // CHECK:STDERR:   ^~~~~~~
+  // CHECK:STDERR:
   fn F();
 }
 
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_todo_facet_lookup.carbon b/toolchain/check/testdata/interface/no_prelude/fail_todo_facet_lookup.carbon
index 07b7eb9cfd58..a9fa2c2cc16f 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_todo_facet_lookup.carbon
+++ b/toolchain/check/testdata/interface/no_prelude/fail_todo_facet_lookup.carbon
@@ -19,9 +19,10 @@ fn CallStatic(T:! Interface) {
 }
 
 fn CallFacet(T:! Interface, x: T) {
-  // CHECK:STDERR: fail_todo_facet_lookup.carbon:[[@LINE+3]]:3: error: type `T` does not support qualified expressions [QualifiedExprUnsupported]
+  // CHECK:STDERR: fail_todo_facet_lookup.carbon:[[@LINE+4]]:3: error: type `T` does not support qualified expressions [QualifiedExprUnsupported]
   // CHECK:STDERR:   x.F();
   // CHECK:STDERR:   ^~~
+  // CHECK:STDERR:
   x.F();
 }
 
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_todo_generic_default_fn.carbon b/toolchain/check/testdata/interface/no_prelude/fail_todo_generic_default_fn.carbon
index 7f4a54793800..96b421ab602f 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_todo_generic_default_fn.carbon
+++ b/toolchain/check/testdata/interface/no_prelude/fail_todo_generic_default_fn.carbon
@@ -13,12 +13,13 @@ interface I(T:! type) {
   fn F[self: Self]() -> Self;
 }
 
-// CHECK:STDERR: fail_todo_generic_default_fn.carbon:[[@LINE+6]]:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
+// CHECK:STDERR: fail_todo_generic_default_fn.carbon:[[@LINE+7]]:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
 // CHECK:STDERR: fn I(T:! type).F[self: Self]() -> Self { return self; }
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_todo_generic_default_fn.carbon:[[@LINE-6]]:3: note: name is previously declared here [NameDeclPrevious]
 // CHECK:STDERR:   fn F[self: Self]() -> Self;
 // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 fn I(T:! type).F[self: Self]() -> Self { return self; }
 
 // CHECK:STDOUT: --- fail_todo_generic_default_fn.carbon
@@ -52,27 +53,27 @@ fn I(T:! type).F[self: Self]() -> Self { return self; }
 // CHECK:STDOUT:     %T.loc11_13.1: type = bind_symbolic_name T, 0, %T.param [symbolic = %T.loc11_13.2 (constants.%T)]
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %.decl: %.type = fn_decl @.1 [symbolic = constants.%.075] {
-// CHECK:STDOUT:     %self.patt: @.1.%Self.as_type.loc22_24.2 (%Self.as_type) = binding_pattern self
-// CHECK:STDOUT:     %self.param_patt: @.1.%Self.as_type.loc22_24.2 (%Self.as_type) = value_param_pattern %self.patt, runtime_param0
-// CHECK:STDOUT:     %return.patt: @.1.%Self.as_type.loc22_24.2 (%Self.as_type) = return_slot_pattern
-// CHECK:STDOUT:     %return.param_patt: @.1.%Self.as_type.loc22_24.2 (%Self.as_type) = out_param_pattern %return.patt, runtime_param1
+// CHECK:STDOUT:     %self.patt: @.1.%Self.as_type.loc23_24.2 (%Self.as_type) = binding_pattern self
+// CHECK:STDOUT:     %self.param_patt: @.1.%Self.as_type.loc23_24.2 (%Self.as_type) = value_param_pattern %self.patt, runtime_param0
+// CHECK:STDOUT:     %return.patt: @.1.%Self.as_type.loc23_24.2 (%Self.as_type) = return_slot_pattern
+// CHECK:STDOUT:     %return.param_patt: @.1.%Self.as_type.loc23_24.2 (%Self.as_type) = out_param_pattern %return.patt, runtime_param1
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %T.param: type = value_param runtime_param<invalid>
-// CHECK:STDOUT:     %T.loc22_6.1: type = bind_symbolic_name T, 0, %T.param [symbolic = %T.loc22_6.2 (constants.%T)]
-// CHECK:STDOUT:     %.loc22_35.1: @.1.%I.type (%I.type.325) = specific_constant @I.%Self.1, @I(constants.%T) [symbolic = %Self (constants.%Self)]
-// CHECK:STDOUT:     %Self.ref.loc22_35: @.1.%I.type (%I.type.325) = name_ref Self, %.loc22_35.1 [symbolic = %Self (constants.%Self)]
-// CHECK:STDOUT:     %Self.as_type.loc22_35: type = facet_access_type %Self.ref.loc22_35 [symbolic = %Self.as_type.loc22_24.2 (constants.%Self.as_type)]
-// CHECK:STDOUT:     %.loc22_35.2: type = converted %Self.ref.loc22_35, %Self.as_type.loc22_35 [symbolic = %Self.as_type.loc22_24.2 (constants.%Self.as_type)]
-// CHECK:STDOUT:     %self.param: @.1.%Self.as_type.loc22_24.2 (%Self.as_type) = value_param runtime_param0
-// CHECK:STDOUT:     %.loc22_24.1: type = splice_block %.loc22_24.3 [symbolic = %Self.as_type.loc22_24.2 (constants.%Self.as_type)] {
-// CHECK:STDOUT:       %.loc22_24.2: @.1.%I.type (%I.type.325) = specific_constant @I.%Self.1, @I(constants.%T) [symbolic = %Self (constants.%Self)]
-// CHECK:STDOUT:       %Self.ref.loc22_24: @.1.%I.type (%I.type.325) = name_ref Self, %.loc22_24.2 [symbolic = %Self (constants.%Self)]
-// CHECK:STDOUT:       %Self.as_type.loc22_24.1: type = facet_access_type %Self.ref.loc22_24 [symbolic = %Self.as_type.loc22_24.2 (constants.%Self.as_type)]
-// CHECK:STDOUT:       %.loc22_24.3: type = converted %Self.ref.loc22_24, %Self.as_type.loc22_24.1 [symbolic = %Self.as_type.loc22_24.2 (constants.%Self.as_type)]
+// CHECK:STDOUT:     %T.loc23_6.1: type = bind_symbolic_name T, 0, %T.param [symbolic = %T.loc23_6.2 (constants.%T)]
+// CHECK:STDOUT:     %.loc23_35.1: @.1.%I.type (%I.type.325) = specific_constant @I.%Self.1, @I(constants.%T) [symbolic = %Self (constants.%Self)]
+// CHECK:STDOUT:     %Self.ref.loc23_35: @.1.%I.type (%I.type.325) = name_ref Self, %.loc23_35.1 [symbolic = %Self (constants.%Self)]
+// CHECK:STDOUT:     %Self.as_type.loc23_35: type = facet_access_type %Self.ref.loc23_35 [symbolic = %Self.as_type.loc23_24.2 (constants.%Self.as_type)]
+// CHECK:STDOUT:     %.loc23_35.2: type = converted %Self.ref.loc23_35, %Self.as_type.loc23_35 [symbolic = %Self.as_type.loc23_24.2 (constants.%Self.as_type)]
+// CHECK:STDOUT:     %self.param: @.1.%Self.as_type.loc23_24.2 (%Self.as_type) = value_param runtime_param0
+// CHECK:STDOUT:     %.loc23_24.1: type = splice_block %.loc23_24.3 [symbolic = %Self.as_type.loc23_24.2 (constants.%Self.as_type)] {
+// CHECK:STDOUT:       %.loc23_24.2: @.1.%I.type (%I.type.325) = specific_constant @I.%Self.1, @I(constants.%T) [symbolic = %Self (constants.%Self)]
+// CHECK:STDOUT:       %Self.ref.loc23_24: @.1.%I.type (%I.type.325) = name_ref Self, %.loc23_24.2 [symbolic = %Self (constants.%Self)]
+// CHECK:STDOUT:       %Self.as_type.loc23_24.1: type = facet_access_type %Self.ref.loc23_24 [symbolic = %Self.as_type.loc23_24.2 (constants.%Self.as_type)]
+// CHECK:STDOUT:       %.loc23_24.3: type = converted %Self.ref.loc23_24, %Self.as_type.loc23_24.1 [symbolic = %Self.as_type.loc23_24.2 (constants.%Self.as_type)]
 // CHECK:STDOUT:     }
-// CHECK:STDOUT:     %self: @.1.%Self.as_type.loc22_24.2 (%Self.as_type) = bind_name self, %self.param
-// CHECK:STDOUT:     %return.param: ref @.1.%Self.as_type.loc22_24.2 (%Self.as_type) = out_param runtime_param1
-// CHECK:STDOUT:     %return: ref @.1.%Self.as_type.loc22_24.2 (%Self.as_type) = return_slot %return.param
+// CHECK:STDOUT:     %self: @.1.%Self.as_type.loc23_24.2 (%Self.as_type) = bind_name self, %self.param
+// CHECK:STDOUT:     %return.param: ref @.1.%Self.as_type.loc23_24.2 (%Self.as_type) = out_param runtime_param1
+// CHECK:STDOUT:     %return: ref @.1.%Self.as_type.loc23_24.2 (%Self.as_type) = return_slot %return.param
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -129,19 +130,19 @@ fn I(T:! type).F[self: Self]() -> Self { return self; }
 // CHECK:STDOUT:   fn[%self.param_patt: @F.%Self.as_type.loc13_14.1 (%Self.as_type)]() -> @F.%Self.as_type.loc13_14.1 (%Self.as_type);
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: generic fn @.1(%T.loc22_6.1: type, @I.%Self.1: @I.%I.type (%I.type.325)) {
-// CHECK:STDOUT:   %T.loc22_6.2: type = bind_symbolic_name T, 0 [symbolic = %T.loc22_6.2 (constants.%T)]
+// CHECK:STDOUT: generic fn @.1(%T.loc23_6.1: type, @I.%Self.1: @I.%I.type (%I.type.325)) {
+// CHECK:STDOUT:   %T.loc23_6.2: type = bind_symbolic_name T, 0 [symbolic = %T.loc23_6.2 (constants.%T)]
 // CHECK:STDOUT:   %T.patt: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt (constants.%T.patt)]
-// CHECK:STDOUT:   %I.type: type = facet_type <@I, @I(%T.loc22_6.2)> [symbolic = %I.type (constants.%I.type.325)]
+// CHECK:STDOUT:   %I.type: type = facet_type <@I, @I(%T.loc23_6.2)> [symbolic = %I.type (constants.%I.type.325)]
 // CHECK:STDOUT:   %Self: %I.type.325 = bind_symbolic_name Self, 1 [symbolic = %Self (constants.%Self)]
-// CHECK:STDOUT:   %Self.as_type.loc22_24.2: type = facet_access_type %Self [symbolic = %Self.as_type.loc22_24.2 (constants.%Self.as_type)]
+// CHECK:STDOUT:   %Self.as_type.loc23_24.2: type = facet_access_type %Self [symbolic = %Self.as_type.loc23_24.2 (constants.%Self.as_type)]
 // CHECK:STDOUT:
 // CHECK:STDOUT: !definition:
-// CHECK:STDOUT:   %require_complete: <witness> = require_complete_type @.1.%Self.as_type.loc22_24.2 (%Self.as_type) [symbolic = %require_complete (constants.%require_complete)]
+// CHECK:STDOUT:   %require_complete: <witness> = require_complete_type @.1.%Self.as_type.loc23_24.2 (%Self.as_type) [symbolic = %require_complete (constants.%require_complete)]
 // CHECK:STDOUT:
-// CHECK:STDOUT:   fn[%self.param_patt: @.1.%Self.as_type.loc22_24.2 (%Self.as_type)]() -> @.1.%Self.as_type.loc22_24.2 (%Self.as_type) {
+// CHECK:STDOUT:   fn[%self.param_patt: @.1.%Self.as_type.loc23_24.2 (%Self.as_type)]() -> @.1.%Self.as_type.loc23_24.2 (%Self.as_type) {
 // CHECK:STDOUT:   !entry:
-// CHECK:STDOUT:     %self.ref: @.1.%Self.as_type.loc22_24.2 (%Self.as_type) = name_ref self, %self
+// CHECK:STDOUT:     %self.ref: @.1.%Self.as_type.loc23_24.2 (%Self.as_type) = name_ref self, %self
 // CHECK:STDOUT:     return %self.ref
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
@@ -171,12 +172,12 @@ fn I(T:! type).F[self: Self]() -> Self { return self; }
 // CHECK:STDOUT: specific @I(%T.loc11_13.2) {}
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @.1(constants.%T, constants.%Self) {
-// CHECK:STDOUT:   %T.loc22_6.2 => constants.%T
+// CHECK:STDOUT:   %T.loc23_6.2 => constants.%T
 // CHECK:STDOUT:   %T.patt => constants.%T
 // CHECK:STDOUT:   %I.type => constants.%I.type.325
 // CHECK:STDOUT:   %Self => constants.%Self
-// CHECK:STDOUT:   %Self.as_type.loc22_24.2 => constants.%Self.as_type
+// CHECK:STDOUT:   %Self.as_type.loc23_24.2 => constants.%Self.as_type
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: specific @I(@.1.%T.loc22_6.2) {}
+// CHECK:STDOUT: specific @I(@.1.%T.loc23_6.2) {}
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_todo_modifiers.carbon b/toolchain/check/testdata/interface/no_prelude/fail_todo_modifiers.carbon
index 83cbde225c2b..6b02baad6af3 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_todo_modifiers.carbon
+++ b/toolchain/check/testdata/interface/no_prelude/fail_todo_modifiers.carbon
@@ -14,9 +14,10 @@ interface Modifiers {
   // CHECK:STDERR:   ^~~~~
   // CHECK:STDERR:
   final fn Final() { }
-  // CHECK:STDERR: fail_todo_modifiers.carbon:[[@LINE+3]]:3: error: semantics TODO: `interface modifier` [SemanticsTodo]
+  // CHECK:STDERR: fail_todo_modifiers.carbon:[[@LINE+4]]:3: error: semantics TODO: `interface modifier` [SemanticsTodo]
   // CHECK:STDERR:   default fn Default() { }
   // CHECK:STDERR:   ^~~~~~~
+  // CHECK:STDERR:
   default fn Default() { }
 }
 
diff --git a/toolchain/check/testdata/interface/no_prelude/generic.carbon b/toolchain/check/testdata/interface/no_prelude/generic.carbon
index c0402d092049..bc3e2953c23f 100644
--- a/toolchain/check/testdata/interface/no_prelude/generic.carbon
+++ b/toolchain/check/testdata/interface/no_prelude/generic.carbon
@@ -49,12 +49,13 @@ class B {}
 fn F(T:! Generic(A));
 fn G(T:! Generic(B)) {
   // TODO: Include generic arguments in the type name.
-  // CHECK:STDERR: fail_mismatched_args.carbon:[[@LINE+6]]:3: error: `Core.ImplicitAs` implicitly referenced here, but package `Core` not found [CoreNotFound]
+  // CHECK:STDERR: fail_mismatched_args.carbon:[[@LINE+7]]:3: error: `Core.ImplicitAs` implicitly referenced here, but package `Core` not found [CoreNotFound]
   // CHECK:STDERR:   F(T);
   // CHECK:STDERR:   ^~~~
   // CHECK:STDERR: fail_mismatched_args.carbon:[[@LINE-6]]:1: note: while deducing parameters of generic declared here [DeductionGenericHere]
   // CHECK:STDERR: fn F(T:! Generic(A));
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   F(T);
 }
 
@@ -485,7 +486,7 @@ fn G(T:! Generic(B)) {
 // CHECK:STDOUT:   !entry:
 // CHECK:STDOUT:     %F.ref: %F.type = name_ref F, file.%F.decl [template = constants.%F]
 // CHECK:STDOUT:     %T.ref: %Generic.type.4ce = name_ref T, %T.loc10_6.1 [symbolic = %T.loc10_6.2 (constants.%T.bae)]
-// CHECK:STDOUT:     %.loc18: %Generic.type.c7c = converted %T.ref, <error> [template = <error>]
+// CHECK:STDOUT:     %.loc19: %Generic.type.c7c = converted %T.ref, <error> [template = <error>]
 // CHECK:STDOUT:     return
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/interface/no_prelude/generic_vs_params.carbon b/toolchain/check/testdata/interface/no_prelude/generic_vs_params.carbon
index e7692b9352f0..959b55342d9c 100644
--- a/toolchain/check/testdata/interface/no_prelude/generic_vs_params.carbon
+++ b/toolchain/check/testdata/interface/no_prelude/generic_vs_params.carbon
@@ -42,9 +42,10 @@ interface A[T: type]() {}
 
 library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_non_generic_params.carbon:[[@LINE+3]]:13: error: parameters of generic types must be constant [GenericParamMustBeConstant]
+// CHECK:STDERR: fail_non_generic_params.carbon:[[@LINE+4]]:13: error: parameters of generic types must be constant [GenericParamMustBeConstant]
 // CHECK:STDERR: interface A(T: type) {}
 // CHECK:STDERR:             ^~~~~~~
+// CHECK:STDERR:
 interface A(T: type) {}
 
 // CHECK:STDOUT: --- params.carbon
diff --git a/toolchain/check/testdata/interface/no_prelude/import_access.carbon b/toolchain/check/testdata/interface/no_prelude/import_access.carbon
index 01a81fd541a2..60ab34895d90 100644
--- a/toolchain/check/testdata/interface/no_prelude/import_access.carbon
+++ b/toolchain/check/testdata/interface/no_prelude/import_access.carbon
@@ -132,9 +132,10 @@ package Other library "[[@TEST_NAME]]";
 
 import Test library "forward";
 
-// CHECK:STDERR: fail_other_forward.carbon:[[@LINE+3]]:9: error: name `Forward` not found [NameNotFound]
+// CHECK:STDERR: fail_other_forward.carbon:[[@LINE+4]]:9: error: name `Forward` not found [NameNotFound]
 // CHECK:STDERR: fn F(i: Forward*) {}
 // CHECK:STDERR:         ^~~~~~~
+// CHECK:STDERR:
 fn F(i: Forward*) {}
 
 // --- todo_fail_private_on_redecl.carbon
@@ -502,7 +503,7 @@ private interface Redecl {}
 // CHECK:STDOUT:     %i.param_patt: <error> = value_param_pattern %i.patt, runtime_param0
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %i.param: <error> = value_param runtime_param0
-// CHECK:STDOUT:     %.loc9: type = splice_block %ptr [template = <error>] {
+// CHECK:STDOUT:     %.loc10: type = splice_block %ptr [template = <error>] {
 // CHECK:STDOUT:       %Forward.ref: <error> = name_ref Forward, <error> [template = <error>]
 // CHECK:STDOUT:       %ptr: type = ptr_type <error> [template = <error>]
 // CHECK:STDOUT:     }
diff --git a/toolchain/check/testdata/interface/no_prelude/import_interface_decl.carbon b/toolchain/check/testdata/interface/no_prelude/import_interface_decl.carbon
index 410936a885e4..06d1b242b3f9 100644
--- a/toolchain/check/testdata/interface/no_prelude/import_interface_decl.carbon
+++ b/toolchain/check/testdata/interface/no_prelude/import_interface_decl.carbon
@@ -18,9 +18,10 @@ impl library "[[@TEST_NAME]]";
 // --- fail_b.carbon
 library "[[@TEST_NAME]]";
 interface B {}
-// CHECK:STDERR: fail_b.carbon:[[@LINE+3]]:1: error: impl declared but not defined [ImplMissingDefinition]
+// CHECK:STDERR: fail_b.carbon:[[@LINE+4]]:1: error: impl declared but not defined [ImplMissingDefinition]
 // CHECK:STDERR: impl () as B;
 // CHECK:STDERR: ^~~~~~~~~~~~~
+// CHECK:STDERR:
 impl () as B;
 
 // --- b.impl.carbon
@@ -70,8 +71,8 @@ impl library "[[@TEST_NAME]]";
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %B.decl: type = interface_decl @B [template = constants.%B.type] {} {}
 // CHECK:STDOUT:   impl_decl @impl [template] {} {
-// CHECK:STDOUT:     %.loc6_7.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc6_7.2: type = converted %.loc6_7.1, constants.%empty_tuple.type [template = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %.loc7_7.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc7_7.2: type = converted %.loc7_7.1, constants.%empty_tuple.type [template = constants.%empty_tuple.type]
 // CHECK:STDOUT:     %B.ref: type = name_ref B, file.%B.decl [template = constants.%B.type]
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %impl_witness: <witness> = impl_witness () [template = constants.%impl_witness]
@@ -85,7 +86,7 @@ impl library "[[@TEST_NAME]]";
 // CHECK:STDOUT:   witness = ()
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl: %.loc6_7.2 as %B.ref;
+// CHECK:STDOUT: impl @impl: %.loc7_7.2 as %B.ref;
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- b.impl.carbon
 // CHECK:STDOUT:
@@ -97,8 +98,8 @@ impl library "[[@TEST_NAME]]";
 // CHECK:STDOUT: imports {
 // CHECK:STDOUT:   %import_ref.8b9 = import_ref Main//b, B, unloaded
 // CHECK:STDOUT:   %import_ref.420 = import_ref Main//b, inst15 [no loc], unloaded
-// CHECK:STDOUT:   %import_ref.e5c: type = import_ref Main//b, loc6_7, loaded [template = constants.%empty_tuple.type]
-// CHECK:STDOUT:   %import_ref.171: type = import_ref Main//b, loc6_12, loaded [template = constants.%B.type]
+// CHECK:STDOUT:   %import_ref.e5c: type = import_ref Main//b, loc7_7, loaded [template = constants.%empty_tuple.type]
+// CHECK:STDOUT:   %import_ref.171: type = import_ref Main//b, loc7_12, loaded [template = constants.%B.type]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
diff --git a/toolchain/check/testdata/interface/no_prelude/syntactic_merge.carbon b/toolchain/check/testdata/interface/no_prelude/syntactic_merge.carbon
index fde8e4c57a3d..1c609cb75ffa 100644
--- a/toolchain/check/testdata/interface/no_prelude/syntactic_merge.carbon
+++ b/toolchain/check/testdata/interface/no_prelude/syntactic_merge.carbon
@@ -173,16 +173,17 @@ library "[[@TEST_NAME]]";
 class C {}
 
 interface Foo(a:! const C);
-// CHECK:STDERR: fail_repeat_const.carbon:[[@LINE+10]]:19: warning: `const` applied repeatedly to the same type has no additional effect [RepeatedConst]
+// CHECK:STDERR: fail_repeat_const.carbon:[[@LINE+11]]:19: warning: `const` applied repeatedly to the same type has no additional effect [RepeatedConst]
 // CHECK:STDERR: interface Foo(a:! const (const C)) {}
 // CHECK:STDERR:                   ^~~~~~~~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_repeat_const.carbon:[[@LINE+6]]:25: error: redeclaration syntax differs here [RedeclParamSyntaxDiffers]
+// CHECK:STDERR: fail_repeat_const.carbon:[[@LINE+7]]:25: error: redeclaration syntax differs here [RedeclParamSyntaxDiffers]
 // CHECK:STDERR: interface Foo(a:! const (const C)) {}
 // CHECK:STDERR:                         ^
 // CHECK:STDERR: fail_repeat_const.carbon:[[@LINE-8]]:25: note: comparing with previous declaration here [RedeclParamSyntaxPrevious]
 // CHECK:STDERR: interface Foo(a:! const C);
 // CHECK:STDERR:                         ^
+// CHECK:STDERR:
 interface Foo(a:! const (const C)) {}
 
 // CHECK:STDOUT: --- basic.carbon
@@ -1135,16 +1136,16 @@ interface Foo(a:! const (const C)) {}
 // CHECK:STDOUT:     %a.loc6_15.1: %const = bind_symbolic_name a, 0, %a.param [symbolic = %a.loc6_15.2 (constants.%a)]
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %.decl: %.type.abf = interface_decl @.1 [template = constants.%.generic] {
-// CHECK:STDOUT:     %a.patt.loc17_15.1: %const = symbolic_binding_pattern a, 0 [symbolic = %a.patt.loc17_15.2 (constants.%a.patt)]
-// CHECK:STDOUT:     %a.param_patt: %const = value_param_pattern %a.patt.loc17_15.1, runtime_param<invalid> [symbolic = %a.patt.loc17_15.2 (constants.%a.patt)]
+// CHECK:STDOUT:     %a.patt.loc18_15.1: %const = symbolic_binding_pattern a, 0 [symbolic = %a.patt.loc18_15.2 (constants.%a.patt)]
+// CHECK:STDOUT:     %a.param_patt: %const = value_param_pattern %a.patt.loc18_15.1, runtime_param<invalid> [symbolic = %a.patt.loc18_15.2 (constants.%a.patt)]
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %a.param: %const = value_param runtime_param<invalid>
-// CHECK:STDOUT:     %.loc17: type = splice_block %const.loc17_19 [template = constants.%const] {
+// CHECK:STDOUT:     %.loc18: type = splice_block %const.loc18_19 [template = constants.%const] {
 // CHECK:STDOUT:       %C.ref: type = name_ref C, file.%C.decl [template = constants.%C]
-// CHECK:STDOUT:       %const.loc17_26: type = const_type %C [template = constants.%const]
-// CHECK:STDOUT:       %const.loc17_19: type = const_type %const [template = constants.%const]
+// CHECK:STDOUT:       %const.loc18_26: type = const_type %C [template = constants.%const]
+// CHECK:STDOUT:       %const.loc18_19: type = const_type %const [template = constants.%const]
 // CHECK:STDOUT:     }
-// CHECK:STDOUT:     %a.loc17_15.1: %const = bind_symbolic_name a, 0, %a.param [symbolic = %a.loc17_15.2 (constants.%a)]
+// CHECK:STDOUT:     %a.loc18_15.1: %const = bind_symbolic_name a, 0, %a.param [symbolic = %a.loc18_15.2 (constants.%a)]
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -1155,12 +1156,12 @@ interface Foo(a:! const (const C)) {}
 // CHECK:STDOUT:   interface;
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: generic interface @.1(%a.loc17_15.1: %const) {
-// CHECK:STDOUT:   %a.loc17_15.2: %const = bind_symbolic_name a, 0 [symbolic = %a.loc17_15.2 (constants.%a)]
-// CHECK:STDOUT:   %a.patt.loc17_15.2: %const = symbolic_binding_pattern a, 0 [symbolic = %a.patt.loc17_15.2 (constants.%a.patt)]
+// CHECK:STDOUT: generic interface @.1(%a.loc18_15.1: %const) {
+// CHECK:STDOUT:   %a.loc18_15.2: %const = bind_symbolic_name a, 0 [symbolic = %a.loc18_15.2 (constants.%a)]
+// CHECK:STDOUT:   %a.patt.loc18_15.2: %const = symbolic_binding_pattern a, 0 [symbolic = %a.patt.loc18_15.2 (constants.%a.patt)]
 // CHECK:STDOUT:
 // CHECK:STDOUT: !definition:
-// CHECK:STDOUT:   %.type: type = facet_type <@.1, @.1(%a.loc17_15.2)> [symbolic = %.type (constants.%.type.963)]
+// CHECK:STDOUT:   %.type: type = facet_type <@.1, @.1(%a.loc18_15.2)> [symbolic = %.type (constants.%.type.963)]
 // CHECK:STDOUT:   %Self.2: %.type.963 = bind_symbolic_name Self, 1 [symbolic = %Self.2 (constants.%Self)]
 // CHECK:STDOUT:
 // CHECK:STDOUT:   interface {
@@ -1183,9 +1184,9 @@ interface Foo(a:! const (const C)) {}
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @.1(constants.%a) {
-// CHECK:STDOUT:   %a.loc17_15.2 => constants.%a
-// CHECK:STDOUT:   %a.patt.loc17_15.2 => constants.%a
+// CHECK:STDOUT:   %a.loc18_15.2 => constants.%a
+// CHECK:STDOUT:   %a.patt.loc18_15.2 => constants.%a
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: specific @.1(%a.loc17_15.2) {}
+// CHECK:STDOUT: specific @.1(%a.loc18_15.2) {}
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/no_prelude/bad_import.carbon b/toolchain/check/testdata/interop/cpp/no_prelude/bad_import.carbon
index 93c587bb80b0..e25c4790012e 100644
--- a/toolchain/check/testdata/interop/cpp/no_prelude/bad_import.carbon
+++ b/toolchain/check/testdata/interop/cpp/no_prelude/bad_import.carbon
@@ -22,11 +22,12 @@ import Cpp;
 
 library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_import_cpp_library_empty.carbon:[[@LINE+5]]:1: error: `Cpp` import missing library [CppInteropMissingLibrary]
+// CHECK:STDERR: fail_import_cpp_library_empty.carbon:[[@LINE+6]]:1: error: `Cpp` import missing library [CppInteropMissingLibrary]
 // CHECK:STDERR: import Cpp library "";
 // CHECK:STDERR: ^~~~~~
 // CHECK:STDERR:
 // CHECK:STDERR: "foo.h": error: error opening file for read: No such file or directory [ErrorOpeningFile]
+// CHECK:STDERR:
 import Cpp library "";
 
 // --- fail_import_cpp_library_file_with_quotes.carbon
diff --git a/toolchain/check/testdata/interop/cpp/no_prelude/cpp_diagnostics.carbon b/toolchain/check/testdata/interop/cpp/no_prelude/cpp_diagnostics.carbon
index 62d411780cc6..b65d2044eb08 100644
--- a/toolchain/check/testdata/interop/cpp/no_prelude/cpp_diagnostics.carbon
+++ b/toolchain/check/testdata/interop/cpp/no_prelude/cpp_diagnostics.carbon
@@ -126,7 +126,7 @@ import Cpp library "one_error_and_one_warning.h";
 
 library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_import_cpp_file_with_multiple_errors_and_multiple_warnings.carbon:[[@LINE+19]]:1: error: 2 errors and 3 warnings in `Cpp` import `multiple_errors_and_multiple_warnings.h`:
+// CHECK:STDERR: fail_import_cpp_file_with_multiple_errors_and_multiple_warnings.carbon:[[@LINE+20]]:1: error: 2 errors and 3 warnings in `Cpp` import `multiple_errors_and_multiple_warnings.h`:
 // CHECK:STDERR: multiple_errors_and_multiple_warnings.h:2:2: error: "error1"
 // CHECK:STDERR:     2 | #error "error1"
 // CHECK:STDERR:       |  ^
@@ -145,6 +145,7 @@ library "[[@TEST_NAME]]";
 // CHECK:STDERR:  [CppInteropParseError]
 // CHECK:STDERR: import Cpp library "multiple_errors_and_multiple_warnings.h";
 // CHECK:STDERR: ^~~~~~
+// CHECK:STDERR:
 import Cpp library "multiple_errors_and_multiple_warnings.h";
 
 // CHECK:STDOUT: --- fail_import_cpp_file_with_one_error.carbon
diff --git a/toolchain/check/testdata/interop/cpp/no_prelude/file_not_found.carbon b/toolchain/check/testdata/interop/cpp/no_prelude/file_not_found.carbon
index 876270079770..794cebf21977 100644
--- a/toolchain/check/testdata/interop/cpp/no_prelude/file_not_found.carbon
+++ b/toolchain/check/testdata/interop/cpp/no_prelude/file_not_found.carbon
@@ -8,6 +8,7 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/no_prelude/file_not_found.carbon
 // CHECK:STDERR: not_found.h: error: error opening file for read: No such file or directory [ErrorOpeningFile]
+// CHECK:STDERR:
 
 // --- fail_cpp_file_not_found.carbon
 
diff --git a/toolchain/check/testdata/interop/cpp/no_prelude/multiple_imports.carbon b/toolchain/check/testdata/interop/cpp/no_prelude/multiple_imports.carbon
index 7e96e21e85fb..e77c6e3d595e 100644
--- a/toolchain/check/testdata/interop/cpp/no_prelude/multiple_imports.carbon
+++ b/toolchain/check/testdata/interop/cpp/no_prelude/multiple_imports.carbon
@@ -21,9 +21,10 @@ void foo1();
 library "[[@TEST_NAME]]";
 
 import Cpp library "file1.h";
-// CHECK:STDERR: fail_multiple_imports.carbon:[[@LINE+3]]:1: error: semantics TODO: `multiple Cpp imports are not yet supported` [SemanticsTodo]
+// CHECK:STDERR: fail_multiple_imports.carbon:[[@LINE+4]]:1: error: semantics TODO: `multiple Cpp imports are not yet supported` [SemanticsTodo]
 // CHECK:STDERR: import Cpp library "file2.h";
 // CHECK:STDERR: ^~~~~~
+// CHECK:STDERR:
 import Cpp library "file2.h";
 
 // CHECK:STDOUT: --- fail_multiple_imports.carbon
diff --git a/toolchain/check/testdata/let/compile_time_bindings.carbon b/toolchain/check/testdata/let/compile_time_bindings.carbon
index 581aa5a5c9fa..67a6a45af98d 100644
--- a/toolchain/check/testdata/let/compile_time_bindings.carbon
+++ b/toolchain/check/testdata/let/compile_time_bindings.carbon
@@ -156,9 +156,10 @@ library "[[@TEST_NAME]]";
 interface Empty {}
 
 impl i32 as Empty {
-  // CHECK:STDERR: fail_use_in_impl.carbon:[[@LINE+3]]:7: error: semantics TODO: ``let` compile time binding outside function or interface` [SemanticsTodo]
+  // CHECK:STDERR: fail_use_in_impl.carbon:[[@LINE+4]]:7: error: semantics TODO: ``let` compile time binding outside function or interface` [SemanticsTodo]
   // CHECK:STDERR:   let Zero:! i32 = 0;
   // CHECK:STDERR:       ^~~~~~~~~~
+  // CHECK:STDERR:
   let Zero:! i32 = 0;
 }
 
@@ -817,9 +818,9 @@ impl i32 as Empty {
 // CHECK:STDOUT:   %Convert.bound: <bound method> = bound_method %int_0, %impl.elem0 [template = constants.%Convert.bound]
 // CHECK:STDOUT:   %Convert.specific_fn: <specific function> = specific_function %Convert.bound, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn]
 // CHECK:STDOUT:   %int.convert_checked: init %i32 = call %Convert.specific_fn(%int_0) [template = constants.%int_0.6a9]
-// CHECK:STDOUT:   %.loc10_21.1: %i32 = value_of_initializer %int.convert_checked [template = constants.%int_0.6a9]
-// CHECK:STDOUT:   %.loc10_21.2: %i32 = converted %int_0, %.loc10_21.1 [template = constants.%int_0.6a9]
-// CHECK:STDOUT:   %Zero: %i32 = bind_name Zero, %.loc10_21.2
+// CHECK:STDOUT:   %.loc11_21.1: %i32 = value_of_initializer %int.convert_checked [template = constants.%int_0.6a9]
+// CHECK:STDOUT:   %.loc11_21.2: %i32 = converted %int_0, %.loc11_21.1 [template = constants.%int_0.6a9]
+// CHECK:STDOUT:   %Zero: %i32 = bind_name Zero, %.loc11_21.2
 // CHECK:STDOUT:
 // CHECK:STDOUT: !members:
 // CHECK:STDOUT:   .Zero = %Zero
diff --git a/toolchain/check/testdata/let/fail_duplicate_decl.carbon b/toolchain/check/testdata/let/fail_duplicate_decl.carbon
index 2152f9a6e449..f0d4b03ea8c1 100644
--- a/toolchain/check/testdata/let/fail_duplicate_decl.carbon
+++ b/toolchain/check/testdata/let/fail_duplicate_decl.carbon
@@ -10,12 +10,13 @@
 
 fn F() {
   let a: i32 = 1;
-  // CHECK:STDERR: fail_duplicate_decl.carbon:[[@LINE+6]]:7: error: duplicate name being declared in the same scope [NameDeclDuplicate]
+  // CHECK:STDERR: fail_duplicate_decl.carbon:[[@LINE+7]]:7: error: duplicate name being declared in the same scope [NameDeclDuplicate]
   // CHECK:STDERR:   let a: i32 = 2;
   // CHECK:STDERR:       ^
   // CHECK:STDERR: fail_duplicate_decl.carbon:[[@LINE-4]]:7: note: name is previously declared here [NameDeclPrevious]
   // CHECK:STDERR:   let a: i32 = 1;
   // CHECK:STDERR:       ^
+  // CHECK:STDERR:
   let a: i32 = 2;
 }
 
@@ -69,13 +70,13 @@ fn F() {
 // CHECK:STDOUT:   %.loc12_17.2: %i32 = converted %int_1, %.loc12_17.1 [template = constants.%int_1.5d2]
 // CHECK:STDOUT:   %a.loc12: %i32 = bind_name a, %.loc12_17.2
 // CHECK:STDOUT:   %int_2: Core.IntLiteral = int_value 2 [template = constants.%int_2.ecc]
-// CHECK:STDOUT:   %impl.elem0.loc19: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
-// CHECK:STDOUT:   %Convert.bound.loc19: <bound method> = bound_method %int_2, %impl.elem0.loc19 [template = constants.%Convert.bound.ef9]
-// CHECK:STDOUT:   %Convert.specific_fn.loc19: <specific function> = specific_function %Convert.bound.loc19, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.787]
-// CHECK:STDOUT:   %int.convert_checked.loc19: init %i32 = call %Convert.specific_fn.loc19(%int_2) [template = constants.%int_2.ef8]
-// CHECK:STDOUT:   %.loc19_17.1: %i32 = value_of_initializer %int.convert_checked.loc19 [template = constants.%int_2.ef8]
-// CHECK:STDOUT:   %.loc19_17.2: %i32 = converted %int_2, %.loc19_17.1 [template = constants.%int_2.ef8]
-// CHECK:STDOUT:   %a.loc19: %i32 = bind_name a, %.loc19_17.2
+// CHECK:STDOUT:   %impl.elem0.loc20: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
+// CHECK:STDOUT:   %Convert.bound.loc20: <bound method> = bound_method %int_2, %impl.elem0.loc20 [template = constants.%Convert.bound.ef9]
+// CHECK:STDOUT:   %Convert.specific_fn.loc20: <specific function> = specific_function %Convert.bound.loc20, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.787]
+// CHECK:STDOUT:   %int.convert_checked.loc20: init %i32 = call %Convert.specific_fn.loc20(%int_2) [template = constants.%int_2.ef8]
+// CHECK:STDOUT:   %.loc20_17.1: %i32 = value_of_initializer %int.convert_checked.loc20 [template = constants.%int_2.ef8]
+// CHECK:STDOUT:   %.loc20_17.2: %i32 = converted %int_2, %.loc20_17.1 [template = constants.%int_2.ef8]
+// CHECK:STDOUT:   %a.loc20: %i32 = bind_name a, %.loc20_17.2
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/let/fail_generic.carbon b/toolchain/check/testdata/let/fail_generic.carbon
index fae1d380b615..d0bb8f253594 100644
--- a/toolchain/check/testdata/let/fail_generic.carbon
+++ b/toolchain/check/testdata/let/fail_generic.carbon
@@ -19,12 +19,13 @@ fn F(a: i32) -> i32 {
   // CHECK:STDERR:   ^~~~~~~~~~~~~
   // CHECK:STDERR:
   let x: T = 5;
-  // CHECK:STDERR: fail_generic.carbon:[[@LINE+6]]:3: error: cannot implicitly convert from `T` to `i32` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_generic.carbon:[[@LINE+7]]:3: error: cannot implicitly convert from `T` to `i32` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   return x;
   // CHECK:STDERR:   ^~~~~~~~~
-  // CHECK:STDERR: fail_generic.carbon:[[@LINE+3]]:3: note: type `T` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR: fail_generic.carbon:[[@LINE+4]]:3: note: type `T` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]
   // CHECK:STDERR:   return x;
   // CHECK:STDERR:   ^~~~~~~~~
+  // CHECK:STDERR:
   return x;
 }
 
@@ -82,7 +83,7 @@ fn F(a: i32) -> i32 {
 // CHECK:STDOUT:   %.loc21: %T = converted %int_5, <error> [template = <error>]
 // CHECK:STDOUT:   %x: %T = bind_name x, <error>
 // CHECK:STDOUT:   %x.ref: %T = name_ref x, %x
-// CHECK:STDOUT:   %.loc28: %i32 = converted %x.ref, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc29: %i32 = converted %x.ref, <error> [template = <error>]
 // CHECK:STDOUT:   return <error>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/let/fail_generic_import.carbon b/toolchain/check/testdata/let/fail_generic_import.carbon
index c3ce359334aa..f0fd9233f845 100644
--- a/toolchain/check/testdata/let/fail_generic_import.carbon
+++ b/toolchain/check/testdata/let/fail_generic_import.carbon
@@ -23,9 +23,10 @@ let T:! type = i32;
 impl package Implicit;
 
 // TODO: Should this be valid?
-// CHECK:STDERR: fail_implicit.impl.carbon:[[@LINE+3]]:8: error: cannot evaluate type expression [TypeExprEvaluationFailure]
+// CHECK:STDERR: fail_implicit.impl.carbon:[[@LINE+4]]:8: error: cannot evaluate type expression [TypeExprEvaluationFailure]
 // CHECK:STDERR: let a: T = 0;
 // CHECK:STDERR:        ^
+// CHECK:STDERR:
 let a: T = 0;
 
 // CHECK:STDOUT: --- fail_implicit.carbon
diff --git a/toolchain/check/testdata/let/fail_missing_value.carbon b/toolchain/check/testdata/let/fail_missing_value.carbon
index 54376f6ddd7d..da14d72cb75a 100644
--- a/toolchain/check/testdata/let/fail_missing_value.carbon
+++ b/toolchain/check/testdata/let/fail_missing_value.carbon
@@ -15,9 +15,10 @@
 let n: i32;
 
 fn F() {
-  // CHECK:STDERR: fail_missing_value.carbon:[[@LINE+3]]:13: error: expected `=`; `let` declaration must have an initializer [ExpectedInitializerAfterLet]
+  // CHECK:STDERR: fail_missing_value.carbon:[[@LINE+4]]:13: error: expected `=`; `let` declaration must have an initializer [ExpectedInitializerAfterLet]
   // CHECK:STDERR:   let n: i32;
   // CHECK:STDERR:             ^
+  // CHECK:STDERR:
   let n: i32;
 }
 
diff --git a/toolchain/check/testdata/let/fail_modifiers.carbon b/toolchain/check/testdata/let/fail_modifiers.carbon
index 9628dca16c74..883617c1010c 100644
--- a/toolchain/check/testdata/let/fail_modifiers.carbon
+++ b/toolchain/check/testdata/let/fail_modifiers.carbon
@@ -71,16 +71,17 @@ default default let g: i32 = 1;
 // CHECK:STDERR:
 protected private let h: i32 = 1;
 
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+10]]:11: error: `protected` repeated on declaration [ModifierRepeated]
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+11]]:11: error: `protected` repeated on declaration [ModifierRepeated]
 // CHECK:STDERR: protected protected let i: i32 = 1;
 // CHECK:STDERR:           ^~~~~~~~~
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+7]]:1: note: `protected` previously appeared here [ModifierPrevious]
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+8]]:1: note: `protected` previously appeared here [ModifierPrevious]
 // CHECK:STDERR: protected protected let i: i32 = 1;
 // CHECK:STDERR: ^~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+3]]:1: error: `protected` not allowed; requires class scope [ModifierProtectedNotAllowed]
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+4]]:1: error: `protected` not allowed; requires class scope [ModifierProtectedNotAllowed]
 // CHECK:STDERR: protected protected let i: i32 = 1;
 // CHECK:STDERR: ^~~~~~~~~
+// CHECK:STDERR:
 protected protected let i: i32 = 1;
 
 // CHECK:STDOUT: --- fail_modifiers.carbon
@@ -180,14 +181,14 @@ protected protected let i: i32 = 1;
 // CHECK:STDOUT:   %.loc72_33.1: %i32 = value_of_initializer %int.convert_checked.loc72 [template = constants.%int_1.5d2]
 // CHECK:STDOUT:   %.loc72_33.2: %i32 = converted %int_1.loc72, %.loc72_33.1 [template = constants.%int_1.5d2]
 // CHECK:STDOUT:   %h: %i32 = bind_name h, %.loc72_33.2
-// CHECK:STDOUT:   %int_1.loc84: Core.IntLiteral = int_value 1 [template = constants.%int_1.5b8]
-// CHECK:STDOUT:   %impl.elem0.loc84: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
-// CHECK:STDOUT:   %Convert.bound.loc84: <bound method> = bound_method %int_1.loc84, %impl.elem0.loc84 [template = constants.%Convert.bound]
-// CHECK:STDOUT:   %Convert.specific_fn.loc84: <specific function> = specific_function %Convert.bound.loc84, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn]
-// CHECK:STDOUT:   %int.convert_checked.loc84: init %i32 = call %Convert.specific_fn.loc84(%int_1.loc84) [template = constants.%int_1.5d2]
-// CHECK:STDOUT:   %.loc84_35.1: %i32 = value_of_initializer %int.convert_checked.loc84 [template = constants.%int_1.5d2]
-// CHECK:STDOUT:   %.loc84_35.2: %i32 = converted %int_1.loc84, %.loc84_35.1 [template = constants.%int_1.5d2]
-// CHECK:STDOUT:   %i: %i32 = bind_name i, %.loc84_35.2
+// CHECK:STDOUT:   %int_1.loc85: Core.IntLiteral = int_value 1 [template = constants.%int_1.5b8]
+// CHECK:STDOUT:   %impl.elem0.loc85: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
+// CHECK:STDOUT:   %Convert.bound.loc85: <bound method> = bound_method %int_1.loc85, %impl.elem0.loc85 [template = constants.%Convert.bound]
+// CHECK:STDOUT:   %Convert.specific_fn.loc85: <specific function> = specific_function %Convert.bound.loc85, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn]
+// CHECK:STDOUT:   %int.convert_checked.loc85: init %i32 = call %Convert.specific_fn.loc85(%int_1.loc85) [template = constants.%int_1.5d2]
+// CHECK:STDOUT:   %.loc85_35.1: %i32 = value_of_initializer %int.convert_checked.loc85 [template = constants.%int_1.5d2]
+// CHECK:STDOUT:   %.loc85_35.2: %i32 = converted %int_1.loc85, %.loc85_35.1 [template = constants.%int_1.5d2]
+// CHECK:STDOUT:   %i: %i32 = bind_name i, %.loc85_35.2
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/let/fail_use_in_init.carbon b/toolchain/check/testdata/let/fail_use_in_init.carbon
index 51f4d97f4567..d14a037988da 100644
--- a/toolchain/check/testdata/let/fail_use_in_init.carbon
+++ b/toolchain/check/testdata/let/fail_use_in_init.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/let/fail_use_in_init.carbon
 
 fn F() {
-  // CHECK:STDERR: fail_use_in_init.carbon:[[@LINE+3]]:16: error: name `a` not found [NameNotFound]
+  // CHECK:STDERR: fail_use_in_init.carbon:[[@LINE+4]]:16: error: name `a` not found [NameNotFound]
   // CHECK:STDERR:   let a: i32 = a;
   // CHECK:STDERR:                ^
+  // CHECK:STDERR:
   let a: i32 = a;
 }
 
diff --git a/toolchain/check/testdata/let/generic_import.carbon b/toolchain/check/testdata/let/generic_import.carbon
index b3814e73a7e2..dd09f2737821 100644
--- a/toolchain/check/testdata/let/generic_import.carbon
+++ b/toolchain/check/testdata/let/generic_import.carbon
@@ -27,9 +27,10 @@ impl package Implicit;
 // CHECK:STDERR:        ^~
 // CHECK:STDERR:
 var a: T*;
-// CHECK:STDERR: fail_implicit.impl.carbon:[[@LINE+3]]:8: error: cannot evaluate type expression [TypeExprEvaluationFailure]
+// CHECK:STDERR: fail_implicit.impl.carbon:[[@LINE+4]]:8: error: cannot evaluate type expression [TypeExprEvaluationFailure]
 // CHECK:STDERR: var b: T = *a;
 // CHECK:STDERR:        ^
+// CHECK:STDERR:
 var b: T = *a;
 
 // CHECK:STDOUT: --- fail_implicit.carbon
@@ -92,7 +93,7 @@ var b: T = *a;
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %a.ref: ref <error> = name_ref a, file.%a
-// CHECK:STDOUT:   %.loc12: ref <error> = deref <error>
+// CHECK:STDOUT:   %.loc13: ref <error> = deref <error>
 // CHECK:STDOUT:   assign file.%b.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/let/no_prelude/import_access.carbon b/toolchain/check/testdata/let/no_prelude/import_access.carbon
index 914dc07fffd2..63e6a21ae4b9 100644
--- a/toolchain/check/testdata/let/no_prelude/import_access.carbon
+++ b/toolchain/check/testdata/let/no_prelude/import_access.carbon
@@ -46,9 +46,10 @@ package Other library "[[@TEST_NAME]]";
 
 import Test library "def";
 
-// CHECK:STDERR: fail_other_def.carbon:[[@LINE+3]]:14: error: member name `v` not found in `Test` [MemberNameNotFoundInScope]
+// CHECK:STDERR: fail_other_def.carbon:[[@LINE+4]]:14: error: member name `v` not found in `Test` [MemberNameNotFoundInScope]
 // CHECK:STDERR: let v2: () = Test.v;
 // CHECK:STDERR:              ^~~~~~
+// CHECK:STDERR:
 let v2: () = Test.v;
 
 // CHECK:STDOUT: --- def.carbon
diff --git a/toolchain/check/testdata/namespace/fail_conflict_after_merge.carbon b/toolchain/check/testdata/namespace/fail_conflict_after_merge.carbon
index cfcc03cc77b6..fdc50b8f273b 100644
--- a/toolchain/check/testdata/namespace/fail_conflict_after_merge.carbon
+++ b/toolchain/check/testdata/namespace/fail_conflict_after_merge.carbon
@@ -38,13 +38,14 @@ fn NS();
 // we don't move it.
 namespace NS;
 
-// CHECK:STDERR: fail_conflict.carbon:[[@LINE+7]]:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
+// CHECK:STDERR: fail_conflict.carbon:[[@LINE+8]]:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
 // CHECK:STDERR: fn NS();
 // CHECK:STDERR: ^~~~~~~~
 // CHECK:STDERR: fail_conflict.carbon:[[@LINE-23]]:1: in import [InImport]
 // CHECK:STDERR: namespace.carbon:4:1: note: name is previously declared here [NameDeclPrevious]
 // CHECK:STDERR: namespace NS;
 // CHECK:STDERR: ^~~~~~~~~~~~~
+// CHECK:STDERR:
 fn NS();
 
 // CHECK:STDOUT: --- namespace.carbon
@@ -93,7 +94,7 @@ fn NS();
 // CHECK:STDOUT:   %NS.loc8: <namespace> = namespace [template] {}
 // CHECK:STDOUT:   %.decl.loc18: %.type.b6a92a.1 = fn_decl @.1 [template = constants.%.d852be.1] {} {}
 // CHECK:STDOUT:   %NS.loc22: <namespace> = namespace [template] {}
-// CHECK:STDOUT:   %.decl.loc31: %.type.b6a92a.2 = fn_decl @.2 [template = constants.%.d852be.2] {} {}
+// CHECK:STDOUT:   %.decl.loc32: %.type.b6a92a.2 = fn_decl @.2 [template = constants.%.d852be.2] {} {}
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @.1();
diff --git a/toolchain/check/testdata/namespace/fail_conflict_imported_namespace_first.carbon b/toolchain/check/testdata/namespace/fail_conflict_imported_namespace_first.carbon
index 9e7a5ac9ae1c..34273c6cc0ee 100644
--- a/toolchain/check/testdata/namespace/fail_conflict_imported_namespace_first.carbon
+++ b/toolchain/check/testdata/namespace/fail_conflict_imported_namespace_first.carbon
@@ -20,13 +20,14 @@ package Example;
 
 import library "namespace";
 
-// CHECK:STDERR: fail_conflict.carbon:[[@LINE+7]]:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
+// CHECK:STDERR: fail_conflict.carbon:[[@LINE+8]]:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
 // CHECK:STDERR: fn NS();
 // CHECK:STDERR: ^~~~~~~~
 // CHECK:STDERR: fail_conflict.carbon:[[@LINE-5]]:1: in import [InImport]
 // CHECK:STDERR: namespace.carbon:4:1: note: name is previously declared here [NameDeclPrevious]
 // CHECK:STDERR: namespace NS;
 // CHECK:STDERR: ^~~~~~~~~~~~~
+// CHECK:STDERR:
 fn NS();
 
 fn NS.Foo();
diff --git a/toolchain/check/testdata/namespace/fail_conflict_imported_namespace_nested.carbon b/toolchain/check/testdata/namespace/fail_conflict_imported_namespace_nested.carbon
index e3dca5294bd7..7a991a124b17 100644
--- a/toolchain/check/testdata/namespace/fail_conflict_imported_namespace_nested.carbon
+++ b/toolchain/check/testdata/namespace/fail_conflict_imported_namespace_nested.carbon
@@ -24,13 +24,14 @@ import Other;
 // CHECK:STDERR: ^~~~~~
 // CHECK:STDERR:
 namespace Other;
-// CHECK:STDERR: fail_conflict.carbon:[[@LINE+7]]:10: error: imported packages cannot be used for declarations [QualifiedDeclOutsidePackage]
+// CHECK:STDERR: fail_conflict.carbon:[[@LINE+8]]:10: error: imported packages cannot be used for declarations [QualifiedDeclOutsidePackage]
 // CHECK:STDERR: fn Other.Nested.F();
 // CHECK:STDERR:          ^~~~~~
 // CHECK:STDERR: fail_conflict.carbon:[[@LINE-12]]:1: in import [InImport]
 // CHECK:STDERR: fn.carbon:3:1: note: package imported here [QualifiedDeclOutsidePackageSource]
 // CHECK:STDERR: namespace Nested;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 fn Other.Nested.F();
 
 // CHECK:STDOUT: --- fn.carbon
diff --git a/toolchain/check/testdata/namespace/fail_conflict_imported_namespace_second.carbon b/toolchain/check/testdata/namespace/fail_conflict_imported_namespace_second.carbon
index 835b13a61a6a..557b53a3b2e8 100644
--- a/toolchain/check/testdata/namespace/fail_conflict_imported_namespace_second.carbon
+++ b/toolchain/check/testdata/namespace/fail_conflict_imported_namespace_second.carbon
@@ -30,13 +30,14 @@ import library "fn";
 // CHECK:STDERR:
 namespace NS;
 
-// CHECK:STDERR: fail_conflict.carbon:[[@LINE+7]]:4: error: name qualifiers are only allowed for entities that provide a scope [QualifiedNameInNonScope]
+// CHECK:STDERR: fail_conflict.carbon:[[@LINE+8]]:4: error: name qualifiers are only allowed for entities that provide a scope [QualifiedNameInNonScope]
 // CHECK:STDERR: fn NS.Foo();
 // CHECK:STDERR:    ^~
 // CHECK:STDERR: fail_conflict.carbon:[[@LINE-15]]:1: in import [InImport]
 // CHECK:STDERR: fn.carbon:4:1: note: referenced non-scope entity declared here [QualifiedNameNonScopeEntity]
 // CHECK:STDERR: fn NS();
 // CHECK:STDERR: ^~~~~~~~
+// CHECK:STDERR:
 fn NS.Foo();
 
 // CHECK:STDOUT: --- fn.carbon
diff --git a/toolchain/check/testdata/namespace/fail_conflict_in_imports_namespace_first.carbon b/toolchain/check/testdata/namespace/fail_conflict_in_imports_namespace_first.carbon
index 6d8d86ba57a5..efe90a96d9d2 100644
--- a/toolchain/check/testdata/namespace/fail_conflict_in_imports_namespace_first.carbon
+++ b/toolchain/check/testdata/namespace/fail_conflict_in_imports_namespace_first.carbon
@@ -25,14 +25,15 @@ fn NS() {}
 
 package Example library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_conflict.carbon:[[@LINE+8]]:1: in import [InImport]
+// CHECK:STDERR: fail_conflict.carbon:[[@LINE+9]]:1: in import [InImport]
 // CHECK:STDERR: fn.carbon:4:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
 // CHECK:STDERR: fn NS() {}
 // CHECK:STDERR: ^~~~~~~~~
-// CHECK:STDERR: fail_conflict.carbon:[[@LINE+4]]:1: in import [InImport]
+// CHECK:STDERR: fail_conflict.carbon:[[@LINE+5]]:1: in import [InImport]
 // CHECK:STDERR: namespace.carbon:4:1: note: name is previously declared here [NameDeclPrevious]
 // CHECK:STDERR: namespace NS;
 // CHECK:STDERR: ^~~~~~~~~~~~~
+// CHECK:STDERR:
 import library "namespace";
 import library "fn";
 
diff --git a/toolchain/check/testdata/namespace/fail_conflict_in_imports_namespace_second.carbon b/toolchain/check/testdata/namespace/fail_conflict_in_imports_namespace_second.carbon
index a16fa3f5c8ce..d8b44b7b1a85 100644
--- a/toolchain/check/testdata/namespace/fail_conflict_in_imports_namespace_second.carbon
+++ b/toolchain/check/testdata/namespace/fail_conflict_in_imports_namespace_second.carbon
@@ -25,14 +25,15 @@ fn NS.Foo() {}
 
 package Example library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_conflict.carbon:[[@LINE+8]]:1: in import [InImport]
+// CHECK:STDERR: fail_conflict.carbon:[[@LINE+9]]:1: in import [InImport]
 // CHECK:STDERR: namespace.carbon:4:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
 // CHECK:STDERR: namespace NS;
 // CHECK:STDERR: ^~~~~~~~~~~~~
-// CHECK:STDERR: fail_conflict.carbon:[[@LINE+4]]:1: in import [InImport]
+// CHECK:STDERR: fail_conflict.carbon:[[@LINE+5]]:1: in import [InImport]
 // CHECK:STDERR: fn.carbon:4:1: note: name is previously declared here [NameDeclPrevious]
 // CHECK:STDERR: fn NS() {}
 // CHECK:STDERR: ^~~~~~~~~
+// CHECK:STDERR:
 import library "fn";
 import library "namespace";
 
diff --git a/toolchain/check/testdata/namespace/fail_decl_in_alias.carbon b/toolchain/check/testdata/namespace/fail_decl_in_alias.carbon
index 027625debf6c..8753b7466cc1 100644
--- a/toolchain/check/testdata/namespace/fail_decl_in_alias.carbon
+++ b/toolchain/check/testdata/namespace/fail_decl_in_alias.carbon
@@ -13,12 +13,13 @@ namespace NS;
 alias ns = NS;
 
 // Aliases can't be used when declaring names.
-// CHECK:STDERR: fail_decl_in_alias.carbon:[[@LINE+6]]:4: error: name qualifiers are only allowed for entities that provide a scope [QualifiedNameInNonScope]
+// CHECK:STDERR: fail_decl_in_alias.carbon:[[@LINE+7]]:4: error: name qualifiers are only allowed for entities that provide a scope [QualifiedNameInNonScope]
 // CHECK:STDERR: fn ns.A() -> i32 { return 0; }
 // CHECK:STDERR:    ^~
 // CHECK:STDERR: fail_decl_in_alias.carbon:[[@LINE-6]]:7: note: referenced non-scope entity declared here [QualifiedNameNonScopeEntity]
 // CHECK:STDERR: alias ns = NS;
 // CHECK:STDERR:       ^~
+// CHECK:STDERR:
 fn ns.A() -> i32 { return 0; }
 
 // CHECK:STDOUT: --- fail_decl_in_alias.carbon
@@ -75,8 +76,8 @@ fn ns.A() -> i32 { return 0; }
 // CHECK:STDOUT:   %Convert.bound: <bound method> = bound_method %int_0, %impl.elem0 [template = constants.%Convert.bound]
 // CHECK:STDOUT:   %Convert.specific_fn: <specific function> = specific_function %Convert.bound, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn]
 // CHECK:STDOUT:   %int.convert_checked: init %i32 = call %Convert.specific_fn(%int_0) [template = constants.%int_0.6a9]
-// CHECK:STDOUT:   %.loc22_28.1: %i32 = value_of_initializer %int.convert_checked [template = constants.%int_0.6a9]
-// CHECK:STDOUT:   %.loc22_28.2: %i32 = converted %int_0, %.loc22_28.1 [template = constants.%int_0.6a9]
-// CHECK:STDOUT:   return %.loc22_28.2
+// CHECK:STDOUT:   %.loc23_28.1: %i32 = value_of_initializer %int.convert_checked [template = constants.%int_0.6a9]
+// CHECK:STDOUT:   %.loc23_28.2: %i32 = converted %int_0, %.loc23_28.1 [template = constants.%int_0.6a9]
+// CHECK:STDOUT:   return %.loc23_28.2
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/namespace/fail_duplicate.carbon b/toolchain/check/testdata/namespace/fail_duplicate.carbon
index bc5c12c38ff5..05cbba196ceb 100644
--- a/toolchain/check/testdata/namespace/fail_duplicate.carbon
+++ b/toolchain/check/testdata/namespace/fail_duplicate.carbon
@@ -13,12 +13,13 @@ namespace Foo;
 fn Foo.Baz() {
 }
 
-// CHECK:STDERR: fail_duplicate.carbon:[[@LINE+6]]:1: error: redefinition of `fn Baz` [RedeclRedef]
+// CHECK:STDERR: fail_duplicate.carbon:[[@LINE+7]]:1: error: redefinition of `fn Baz` [RedeclRedef]
 // CHECK:STDERR: fn Foo.Baz() {
 // CHECK:STDERR: ^~~~~~~~~~~~~~
 // CHECK:STDERR: fail_duplicate.carbon:[[@LINE-6]]:1: note: previously defined here [RedeclPrevDef]
 // CHECK:STDERR: fn Foo.Baz() {
 // CHECK:STDERR: ^~~~~~~~~~~~~~
+// CHECK:STDERR:
 fn Foo.Baz() {
 }
 
diff --git a/toolchain/check/testdata/namespace/fail_modifiers.carbon b/toolchain/check/testdata/namespace/fail_modifiers.carbon
index 6002488c900c..57738cae09bd 100644
--- a/toolchain/check/testdata/namespace/fail_modifiers.carbon
+++ b/toolchain/check/testdata/namespace/fail_modifiers.carbon
@@ -49,9 +49,10 @@ private extern abstract base default final namespace A;
 // CHECK:STDERR:
 impl namespace B;
 
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+3]]:1: error: `extern` not allowed on `namespace` declaration [ModifierNotAllowedOnDeclaration]
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+4]]:1: error: `extern` not allowed on `namespace` declaration [ModifierNotAllowedOnDeclaration]
 // CHECK:STDERR: extern namespace C;
 // CHECK:STDERR: ^~~~~~
+// CHECK:STDERR:
 extern namespace C;
 
 // CHECK:STDOUT: --- fail_modifiers.carbon
diff --git a/toolchain/check/testdata/namespace/fail_not_top_level.carbon b/toolchain/check/testdata/namespace/fail_not_top_level.carbon
index 8137f5aec6de..98ec03b5da0e 100644
--- a/toolchain/check/testdata/namespace/fail_not_top_level.carbon
+++ b/toolchain/check/testdata/namespace/fail_not_top_level.carbon
@@ -27,9 +27,10 @@ class C {
 }
 
 interface I {
-  // CHECK:STDERR: fail_not_top_level.carbon:[[@LINE+3]]:3: error: `namespace` declaration not at top level [NamespaceDeclNotAtTopLevel]
+  // CHECK:STDERR: fail_not_top_level.carbon:[[@LINE+4]]:3: error: `namespace` declaration not at top level [NamespaceDeclNotAtTopLevel]
   // CHECK:STDERR:   namespace N;
   // CHECK:STDERR:   ^~~~~~~~~~~~
+  // CHECK:STDERR:
   namespace N;
   fn N.I() {}
 }
diff --git a/toolchain/check/testdata/namespace/fail_params.carbon b/toolchain/check/testdata/namespace/fail_params.carbon
index 864beddc2421..5bc1b7dc4c2e 100644
--- a/toolchain/check/testdata/namespace/fail_params.carbon
+++ b/toolchain/check/testdata/namespace/fail_params.carbon
@@ -30,12 +30,13 @@ namespace B(n: i32);
 namespace C[T:! type](x: T);
 
 namespace D;
-// CHECK:STDERR: fail_params.carbon:[[@LINE+6]]:4: error: redeclaration differs because of parameter list [RedeclParamListDiffers]
+// CHECK:STDERR: fail_params.carbon:[[@LINE+7]]:4: error: redeclaration differs because of parameter list [RedeclParamListDiffers]
 // CHECK:STDERR: fn D(T:! type).F() {}
 // CHECK:STDERR:    ^
 // CHECK:STDERR: fail_params.carbon:[[@LINE-4]]:1: note: previously declared without parameter list [RedeclParamListPrevious]
 // CHECK:STDERR: namespace D;
 // CHECK:STDERR: ^~~~~~~~~~~~
+// CHECK:STDERR:
 fn D(T:! type).F() {}
 
 // CHECK:STDOUT: --- fail_params.carbon
@@ -88,7 +89,7 @@ fn D(T:! type).F() {}
 // CHECK:STDOUT:   %D: <namespace> = namespace [template] {}
 // CHECK:STDOUT:   %.decl: %.type = fn_decl @.1 [template = constants.%.d85] {} {
 // CHECK:STDOUT:     %T.param: type = value_param runtime_param<invalid>
-// CHECK:STDOUT:     %T.loc39_6.1: type = bind_symbolic_name T, 0, %T.param [symbolic = %T.loc39_6.2 (constants.%T)]
+// CHECK:STDOUT:     %T.loc40_6.1: type = bind_symbolic_name T, 0, %T.param [symbolic = %T.loc40_6.2 (constants.%T)]
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -97,8 +98,8 @@ fn D(T:! type).F() {}
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: generic fn @.1(%T.loc39_6.1: type) {
-// CHECK:STDOUT:   %T.loc39_6.2: type = bind_symbolic_name T, 0 [symbolic = %T.loc39_6.2 (constants.%T)]
+// CHECK:STDOUT: generic fn @.1(%T.loc40_6.1: type) {
+// CHECK:STDOUT:   %T.loc40_6.2: type = bind_symbolic_name T, 0 [symbolic = %T.loc40_6.2 (constants.%T)]
 // CHECK:STDOUT:   %T.patt: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt (constants.%T.patt)]
 // CHECK:STDOUT:
 // CHECK:STDOUT: !definition:
@@ -110,7 +111,7 @@ fn D(T:! type).F() {}
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @.1(constants.%T) {
-// CHECK:STDOUT:   %T.loc39_6.2 => constants.%T
+// CHECK:STDOUT:   %T.loc40_6.2 => constants.%T
 // CHECK:STDOUT:   %T.patt => constants.%T
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/namespace/fail_unresolved_scope.carbon b/toolchain/check/testdata/namespace/fail_unresolved_scope.carbon
index d471f4042a52..99a45b810a52 100644
--- a/toolchain/check/testdata/namespace/fail_unresolved_scope.carbon
+++ b/toolchain/check/testdata/namespace/fail_unresolved_scope.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/namespace/fail_unresolved_scope.carbon
 
-// CHECK:STDERR: fail_unresolved_scope.carbon:[[@LINE+3]]:4: error: name `Foo` not found [NameNotFound]
+// CHECK:STDERR: fail_unresolved_scope.carbon:[[@LINE+4]]:4: error: name `Foo` not found [NameNotFound]
 // CHECK:STDERR: fn Foo.Baz() {
 // CHECK:STDERR:    ^~~
+// CHECK:STDERR:
 fn Foo.Baz() {
 }
 
diff --git a/toolchain/check/testdata/namespace/imported_indirect.carbon b/toolchain/check/testdata/namespace/imported_indirect.carbon
index cbb9cad0c5c6..631333523661 100644
--- a/toolchain/check/testdata/namespace/imported_indirect.carbon
+++ b/toolchain/check/testdata/namespace/imported_indirect.carbon
@@ -73,7 +73,7 @@ package Other library "[[@TEST_NAME]]";
 
 import Same library "b";
 
-// CHECK:STDERR: fail_named_indirectly_different_package.carbon:[[@LINE+12]]:10: error: function returns incomplete type `Same.A.C` [IncompleteTypeInFunctionReturnType]
+// CHECK:STDERR: fail_named_indirectly_different_package.carbon:[[@LINE+13]]:10: error: function returns incomplete type `Same.A.C` [IncompleteTypeInFunctionReturnType]
 // CHECK:STDERR: fn G() { Same.F(); }
 // CHECK:STDERR:          ^~~~~~~~
 // CHECK:STDERR: fail_named_indirectly_different_package.carbon:[[@LINE-5]]:1: in import [InImport]
@@ -85,6 +85,7 @@ import Same library "b";
 // CHECK:STDERR: b.carbon:7:8: note: return type declared here [IncompleteReturnTypeHere]
 // CHECK:STDERR: fn F() -> A.C;
 // CHECK:STDERR:        ^~~~~~
+// CHECK:STDERR:
 fn G() { Same.F(); }
 
 // CHECK:STDOUT: --- a.carbon
diff --git a/toolchain/check/testdata/operators/builtin/fail_and_or_not_in_function.carbon b/toolchain/check/testdata/operators/builtin/fail_and_or_not_in_function.carbon
index 0330e1bc949e..dc15e8c0adb2 100644
--- a/toolchain/check/testdata/operators/builtin/fail_and_or_not_in_function.carbon
+++ b/toolchain/check/testdata/operators/builtin/fail_and_or_not_in_function.carbon
@@ -48,17 +48,18 @@ var and_val: bool = true and true;
 // CHECK:STDERR:
 var or_: F(true or true);
 
-// CHECK:STDERR: fail_and_or_not_in_function.carbon:[[@LINE+11]]:20: error: semantics TODO: `Control flow expressions are currently only supported inside functions.` [SemanticsTodo]
+// CHECK:STDERR: fail_and_or_not_in_function.carbon:[[@LINE+12]]:20: error: semantics TODO: `Control flow expressions are currently only supported inside functions.` [SemanticsTodo]
 // CHECK:STDERR: var or_val: bool = true or true;
 // CHECK:STDERR:                    ^~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_and_or_not_in_function.carbon:[[@LINE+7]]:20: error: semantics TODO: `Control flow expressions are currently only supported inside functions.` [SemanticsTodo]
+// CHECK:STDERR: fail_and_or_not_in_function.carbon:[[@LINE+8]]:20: error: semantics TODO: `Control flow expressions are currently only supported inside functions.` [SemanticsTodo]
 // CHECK:STDERR: var or_val: bool = true or true;
 // CHECK:STDERR:                    ^~~~~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_and_or_not_in_function.carbon:[[@LINE+3]]:20: error: semantics TODO: `Control flow expressions are currently only supported inside functions.` [SemanticsTodo]
+// CHECK:STDERR: fail_and_or_not_in_function.carbon:[[@LINE+4]]:20: error: semantics TODO: `Control flow expressions are currently only supported inside functions.` [SemanticsTodo]
 // CHECK:STDERR: var or_val: bool = true or true;
 // CHECK:STDERR:                    ^~~~~~~~~~~~
+// CHECK:STDERR:
 var or_val: bool = true or true;
 
 // CHECK:STDOUT: --- fail_and_or_not_in_function.carbon
diff --git a/toolchain/check/testdata/operators/builtin/fail_and_or_partial_constant.carbon b/toolchain/check/testdata/operators/builtin/fail_and_or_partial_constant.carbon
index 9f917c1a3698..044768c4b675 100644
--- a/toolchain/check/testdata/operators/builtin/fail_and_or_partial_constant.carbon
+++ b/toolchain/check/testdata/operators/builtin/fail_and_or_partial_constant.carbon
@@ -37,9 +37,10 @@ fn KnownValueButNonConstantCondition(x: bool) {
   // CHECK:STDERR:          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   // CHECK:STDERR:
   var c: if x and false then bool else ();
-  // CHECK:STDERR: fail_despite_known_result.carbon:[[@LINE+3]]:10: error: cannot evaluate type expression [TypeExprEvaluationFailure]
+  // CHECK:STDERR: fail_despite_known_result.carbon:[[@LINE+4]]:10: error: cannot evaluate type expression [TypeExprEvaluationFailure]
   // CHECK:STDERR:   var d: if x or true then bool else ();
   // CHECK:STDERR:          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   var d: if x or true then bool else ();
 }
 
diff --git a/toolchain/check/testdata/operators/builtin/fail_assignment_to_error.carbon b/toolchain/check/testdata/operators/builtin/fail_assignment_to_error.carbon
index d678ec4052b9..3b3010b13052 100644
--- a/toolchain/check/testdata/operators/builtin/fail_assignment_to_error.carbon
+++ b/toolchain/check/testdata/operators/builtin/fail_assignment_to_error.carbon
@@ -14,9 +14,10 @@ fn Main() {
   // CHECK:STDERR:   ^~~~~~~~~~
   // CHECK:STDERR:
   undeclared = 42;
-  // CHECK:STDERR: fail_assignment_to_error.carbon:[[@LINE+3]]:4: error: name `also_undeclared` not found [NameNotFound]
+  // CHECK:STDERR: fail_assignment_to_error.carbon:[[@LINE+4]]:4: error: name `also_undeclared` not found [NameNotFound]
   // CHECK:STDERR:   *also_undeclared = 42;
   // CHECK:STDERR:    ^~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   *also_undeclared = 42;
 }
 
@@ -50,9 +51,9 @@ fn Main() {
 // CHECK:STDOUT:   %int_42.loc16: Core.IntLiteral = int_value 42 [template = constants.%int_42]
 // CHECK:STDOUT:   assign %undeclared.ref, <error>
 // CHECK:STDOUT:   %also_undeclared.ref: <error> = name_ref also_undeclared, <error> [template = <error>]
-// CHECK:STDOUT:   %.loc20: ref <error> = deref <error>
-// CHECK:STDOUT:   %int_42.loc20: Core.IntLiteral = int_value 42 [template = constants.%int_42]
-// CHECK:STDOUT:   assign %.loc20, <error>
+// CHECK:STDOUT:   %.loc21: ref <error> = deref <error>
+// CHECK:STDOUT:   %int_42.loc21: Core.IntLiteral = int_value 42 [template = constants.%int_42]
+// CHECK:STDOUT:   assign %.loc21, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/operators/builtin/fail_assignment_to_non_assignable.carbon b/toolchain/check/testdata/operators/builtin/fail_assignment_to_non_assignable.carbon
index e69caa6032a0..aa0bd2fcad92 100644
--- a/toolchain/check/testdata/operators/builtin/fail_assignment_to_non_assignable.carbon
+++ b/toolchain/check/testdata/operators/builtin/fail_assignment_to_non_assignable.carbon
@@ -50,9 +50,10 @@ fn Main() {
 
   // Under #911, if expressions are never reference expressions.
   var a: i32;
-  // CHECK:STDERR: fail_assignment_to_non_assignable.carbon:[[@LINE+3]]:3: error: expression is not assignable [AssignmentToNonAssignable]
+  // CHECK:STDERR: fail_assignment_to_non_assignable.carbon:[[@LINE+4]]:3: error: expression is not assignable [AssignmentToNonAssignable]
   // CHECK:STDERR:   (if true then a else a) = 10;
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   (if true then a else a) = 10;
 }
 
@@ -254,28 +255,28 @@ fn Main() {
 // CHECK:STDOUT:   assign %.loc49_4, %.loc49_27
 // CHECK:STDOUT:   %a.var: ref %i32 = var a
 // CHECK:STDOUT:   %a: ref %i32 = bind_name a, %a.var
-// CHECK:STDOUT:   %true.loc56: bool = bool_literal true [template = constants.%true]
-// CHECK:STDOUT:   if %true.loc56 br !if.expr.then.loc56 else br !if.expr.else.loc56
+// CHECK:STDOUT:   %true.loc57: bool = bool_literal true [template = constants.%true]
+// CHECK:STDOUT:   if %true.loc57 br !if.expr.then.loc57 else br !if.expr.else.loc57
 // CHECK:STDOUT:
-// CHECK:STDOUT: !if.expr.then.loc56:
-// CHECK:STDOUT:   %a.ref.loc56_17: ref %i32 = name_ref a, %a
-// CHECK:STDOUT:   %.loc56_17: %i32 = bind_value %a.ref.loc56_17
-// CHECK:STDOUT:   br !if.expr.result.loc56(%.loc56_17)
+// CHECK:STDOUT: !if.expr.then.loc57:
+// CHECK:STDOUT:   %a.ref.loc57_17: ref %i32 = name_ref a, %a
+// CHECK:STDOUT:   %.loc57_17: %i32 = bind_value %a.ref.loc57_17
+// CHECK:STDOUT:   br !if.expr.result.loc57(%.loc57_17)
 // CHECK:STDOUT:
-// CHECK:STDOUT: !if.expr.else.loc56:
-// CHECK:STDOUT:   %a.ref.loc56_24: ref %i32 = name_ref a, %a
-// CHECK:STDOUT:   %.loc56_24: %i32 = bind_value %a.ref.loc56_24
-// CHECK:STDOUT:   br !if.expr.result.loc56(%.loc56_24)
+// CHECK:STDOUT: !if.expr.else.loc57:
+// CHECK:STDOUT:   %a.ref.loc57_24: ref %i32 = name_ref a, %a
+// CHECK:STDOUT:   %.loc57_24: %i32 = bind_value %a.ref.loc57_24
+// CHECK:STDOUT:   br !if.expr.result.loc57(%.loc57_24)
 // CHECK:STDOUT:
-// CHECK:STDOUT: !if.expr.result.loc56:
-// CHECK:STDOUT:   %.loc56_4: %i32 = block_arg !if.expr.result.loc56
+// CHECK:STDOUT: !if.expr.result.loc57:
+// CHECK:STDOUT:   %.loc57_4: %i32 = block_arg !if.expr.result.loc57
 // CHECK:STDOUT:   %int_10: Core.IntLiteral = int_value 10 [template = constants.%int_10.64f]
-// CHECK:STDOUT:   %impl.elem0.loc56: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
-// CHECK:STDOUT:   %Convert.bound.loc56: <bound method> = bound_method %int_10, %impl.elem0.loc56 [template = constants.%Convert.bound.491]
-// CHECK:STDOUT:   %Convert.specific_fn.loc56: <specific function> = specific_function %Convert.bound.loc56, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.e67]
-// CHECK:STDOUT:   %int.convert_checked.loc56: init %i32 = call %Convert.specific_fn.loc56(%int_10) [template = constants.%int_10.265]
-// CHECK:STDOUT:   %.loc56_27: init %i32 = converted %int_10, %int.convert_checked.loc56 [template = constants.%int_10.265]
-// CHECK:STDOUT:   assign %.loc56_4, %.loc56_27
+// CHECK:STDOUT:   %impl.elem0.loc57: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
+// CHECK:STDOUT:   %Convert.bound.loc57: <bound method> = bound_method %int_10, %impl.elem0.loc57 [template = constants.%Convert.bound.491]
+// CHECK:STDOUT:   %Convert.specific_fn.loc57: <specific function> = specific_function %Convert.bound.loc57, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.e67]
+// CHECK:STDOUT:   %int.convert_checked.loc57: init %i32 = call %Convert.specific_fn.loc57(%int_10) [template = constants.%int_10.265]
+// CHECK:STDOUT:   %.loc57_27: init %i32 = converted %int_10, %int.convert_checked.loc57 [template = constants.%int_10.265]
+// CHECK:STDOUT:   assign %.loc57_4, %.loc57_27
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/operators/builtin/fail_redundant_compound_access.carbon b/toolchain/check/testdata/operators/builtin/fail_redundant_compound_access.carbon
index cd4bd77a95f1..04850f00cb64 100644
--- a/toolchain/check/testdata/operators/builtin/fail_redundant_compound_access.carbon
+++ b/toolchain/check/testdata/operators/builtin/fail_redundant_compound_access.carbon
@@ -17,9 +17,10 @@ fn Main() {
   // CHECK:STDERR:       ^~~~~
   // CHECK:STDERR:
   a = a.(a);
-  // CHECK:STDERR: fail_redundant_compound_access.carbon:[[@LINE+3]]:7: error: member name of type `<type of F>` in compound member access is not an instance member or an interface member [CompoundMemberAccessDoesNotUseBase]
+  // CHECK:STDERR: fail_redundant_compound_access.carbon:[[@LINE+4]]:7: error: member name of type `<type of F>` in compound member access is not an instance member or an interface member [CompoundMemberAccessDoesNotUseBase]
   // CHECK:STDERR:   a = a.(F)();
   // CHECK:STDERR:       ^~~~~
+  // CHECK:STDERR:
   a = a.(F)();
 }
 
@@ -102,11 +103,11 @@ fn Main() {
 // CHECK:STDOUT:   %a.ref.loc19_10: ref %i32 = name_ref a, %a
 // CHECK:STDOUT:   %.loc19: %i32 = bind_value %a.ref.loc19_10
 // CHECK:STDOUT:   assign %a.ref.loc19_3, %.loc19
-// CHECK:STDOUT:   %a.ref.loc23_3: ref %i32 = name_ref a, %a
-// CHECK:STDOUT:   %a.ref.loc23_7: ref %i32 = name_ref a, %a
+// CHECK:STDOUT:   %a.ref.loc24_3: ref %i32 = name_ref a, %a
+// CHECK:STDOUT:   %a.ref.loc24_7: ref %i32 = name_ref a, %a
 // CHECK:STDOUT:   %F.ref: %F.type = name_ref F, file.%F.decl [template = constants.%F]
 // CHECK:STDOUT:   %F.call: init %i32 = call %F.ref()
-// CHECK:STDOUT:   assign %a.ref.loc23_3, %F.call
+// CHECK:STDOUT:   assign %a.ref.loc24_3, %F.call
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/operators/builtin/fail_type_mismatch.carbon b/toolchain/check/testdata/operators/builtin/fail_type_mismatch.carbon
index d11f4131fc72..905e10b379d2 100644
--- a/toolchain/check/testdata/operators/builtin/fail_type_mismatch.carbon
+++ b/toolchain/check/testdata/operators/builtin/fail_type_mismatch.carbon
@@ -9,12 +9,13 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/operators/builtin/fail_type_mismatch.carbon
 
 fn Main() {
-  // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+6]]:17: error: cannot implicitly convert from `Core.IntLiteral` to `bool` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+7]]:17: error: cannot implicitly convert from `Core.IntLiteral` to `bool` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   var x: bool = not 12;
   // CHECK:STDERR:                 ^~~~~~
-  // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+3]]:17: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(bool)` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+4]]:17: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(bool)` [MissingImplInMemberAccessNote]
   // CHECK:STDERR:   var x: bool = not 12;
   // CHECK:STDERR:                 ^~~~~~
+  // CHECK:STDERR:
   var x: bool = not 12;
 }
 
@@ -49,8 +50,8 @@ fn Main() {
 // CHECK:STDOUT:   %x.var: ref bool = var x
 // CHECK:STDOUT:   %x: ref bool = bind_name x, %x.var
 // CHECK:STDOUT:   %int_12: Core.IntLiteral = int_value 12 [template = constants.%int_12]
-// CHECK:STDOUT:   %.loc18_17.1: bool = converted %int_12, <error> [template = <error>]
-// CHECK:STDOUT:   %.loc18_17.2: <error> = not <error> [template = <error>]
+// CHECK:STDOUT:   %.loc19_17.1: bool = converted %int_12, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc19_17.2: <error> = not <error> [template = <error>]
 // CHECK:STDOUT:   assign %x.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/operators/builtin/fail_type_mismatch_assignment.carbon b/toolchain/check/testdata/operators/builtin/fail_type_mismatch_assignment.carbon
index b71ffdcb6cfa..851bed87236a 100644
--- a/toolchain/check/testdata/operators/builtin/fail_type_mismatch_assignment.carbon
+++ b/toolchain/check/testdata/operators/builtin/fail_type_mismatch_assignment.carbon
@@ -10,12 +10,13 @@
 
 fn Main() {
   var a: i32 = 3;
-  // CHECK:STDERR: fail_type_mismatch_assignment.carbon:[[@LINE+6]]:3: error: cannot implicitly convert from `f64` to `i32` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_type_mismatch_assignment.carbon:[[@LINE+7]]:3: error: cannot implicitly convert from `f64` to `i32` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   a = 5.6;
   // CHECK:STDERR:   ^~~~~~~
-  // CHECK:STDERR: fail_type_mismatch_assignment.carbon:[[@LINE+3]]:3: note: type `f64` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR: fail_type_mismatch_assignment.carbon:[[@LINE+4]]:3: note: type `f64` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]
   // CHECK:STDERR:   a = 5.6;
   // CHECK:STDERR:   ^~~~~~~
+  // CHECK:STDERR:
   a = 5.6;
 }
 
@@ -68,7 +69,7 @@ fn Main() {
 // CHECK:STDOUT:   assign %a.var, %.loc12
 // CHECK:STDOUT:   %a.ref: ref %i32 = name_ref a, %a
 // CHECK:STDOUT:   %float: f64 = float_literal 5.6000000000000005 [template = constants.%float]
-// CHECK:STDOUT:   %.loc19: %i32 = converted %float, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc20: %i32 = converted %float, <error> [template = <error>]
 // CHECK:STDOUT:   assign %a.ref, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/operators/builtin/fail_type_mismatch_once.carbon b/toolchain/check/testdata/operators/builtin/fail_type_mismatch_once.carbon
index ee7e9c3761a1..91dc89990883 100644
--- a/toolchain/check/testdata/operators/builtin/fail_type_mismatch_once.carbon
+++ b/toolchain/check/testdata/operators/builtin/fail_type_mismatch_once.carbon
@@ -11,9 +11,10 @@
 fn Main() -> i32 {
   // The following line has two mismatches, but after the first, it shouldn't
   // keep erroring.
-  // CHECK:STDERR: fail_type_mismatch_once.carbon:[[@LINE+3]]:10: error: cannot access member of interface `Core.Add` in type `{}` that does not implement that interface [MissingImplInMemberAccess]
+  // CHECK:STDERR: fail_type_mismatch_once.carbon:[[@LINE+4]]:10: error: cannot access member of interface `Core.Add` in type `{}` that does not implement that interface [MissingImplInMemberAccess]
   // CHECK:STDERR:   return {} + 3.4 + 12;
   // CHECK:STDERR:          ^~~~~~~~
+  // CHECK:STDERR:
   return {} + 3.4 + 12;
 }
 
@@ -58,7 +59,7 @@ fn Main() -> i32 {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @Main() -> %i32 {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %.loc17: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %.loc18: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:   %float: f64 = float_literal 3.4000000000000004 [template = constants.%float]
 // CHECK:STDOUT:   %int_12: Core.IntLiteral = int_value 12 [template = constants.%int_12]
 // CHECK:STDOUT:   %impl.elem0: %Op.type = impl_witness_access <error>, element0 [template = <error>]
diff --git a/toolchain/check/testdata/operators/builtin/fail_unimplemented_op.carbon b/toolchain/check/testdata/operators/builtin/fail_unimplemented_op.carbon
index 023c25472562..cb64b68f63e2 100644
--- a/toolchain/check/testdata/operators/builtin/fail_unimplemented_op.carbon
+++ b/toolchain/check/testdata/operators/builtin/fail_unimplemented_op.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/operators/builtin/fail_unimplemented_op.carbon
 
 fn Main() -> i32 {
-  // CHECK:STDERR: fail_unimplemented_op.carbon:[[@LINE+3]]:10: error: cannot access member of interface `Core.Add` in type `{}` that does not implement that interface [MissingImplInMemberAccess]
+  // CHECK:STDERR: fail_unimplemented_op.carbon:[[@LINE+4]]:10: error: cannot access member of interface `Core.Add` in type `{}` that does not implement that interface [MissingImplInMemberAccess]
   // CHECK:STDERR:   return {} + 34;
   // CHECK:STDERR:          ^~~~~~~
+  // CHECK:STDERR:
   return {} + 34;
 }
 
@@ -54,7 +55,7 @@ fn Main() -> i32 {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @Main() -> %i32 {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %.loc15: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %.loc16: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:   %int_34: Core.IntLiteral = int_value 34 [template = constants.%int_34]
 // CHECK:STDOUT:   return <error>
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/operators/overloaded/eq.carbon b/toolchain/check/testdata/operators/overloaded/eq.carbon
index 79ddfa6cf794..e32385723dcb 100644
--- a/toolchain/check/testdata/operators/overloaded/eq.carbon
+++ b/toolchain/check/testdata/operators/overloaded/eq.carbon
@@ -76,9 +76,10 @@ fn TestRhsBad(a: C, b: D) -> bool {
 }
 
 fn TestLhsBad(a: D, b: C) -> bool {
-  // CHECK:STDERR: fail_no_impl_for_args.carbon:[[@LINE+3]]:10: error: cannot access member of interface `Core.Eq` in type `D` that does not implement that interface [MissingImplInMemberAccess]
+  // CHECK:STDERR: fail_no_impl_for_args.carbon:[[@LINE+4]]:10: error: cannot access member of interface `Core.Eq` in type `D` that does not implement that interface [MissingImplInMemberAccess]
   // CHECK:STDERR:   return a != b;
   // CHECK:STDERR:          ^~~~~~
+  // CHECK:STDERR:
   return a != b;
 }
 
diff --git a/toolchain/check/testdata/operators/overloaded/fail_assign_non_ref.carbon b/toolchain/check/testdata/operators/overloaded/fail_assign_non_ref.carbon
index 54828c511060..aca915ded687 100644
--- a/toolchain/check/testdata/operators/overloaded/fail_assign_non_ref.carbon
+++ b/toolchain/check/testdata/operators/overloaded/fail_assign_non_ref.carbon
@@ -31,12 +31,13 @@ fn TestIncNonRef(a: C) {
 }
 
 fn TestAddAssignNonRef(a: C, b: C) {
-  // CHECK:STDERR: fail_assign_non_ref.carbon:[[@LINE+6]]:3: error: `addr self` method cannot be invoked on a value [AddrSelfIsNonRef]
+  // CHECK:STDERR: fail_assign_non_ref.carbon:[[@LINE+7]]:3: error: `addr self` method cannot be invoked on a value [AddrSelfIsNonRef]
   // CHECK:STDERR:   a += b;
   // CHECK:STDERR:   ^
   // CHECK:STDERR: fail_assign_non_ref.carbon:[[@LINE-18]]:9: note: initializing function parameter [InCallToFunctionParam]
   // CHECK:STDERR:   fn Op[addr self: C*](other: C);
   // CHECK:STDERR:         ^~~~~~~~~~~~~
+  // CHECK:STDERR:
   a += b;
 }
 
diff --git a/toolchain/check/testdata/operators/overloaded/fail_error_recovery.carbon b/toolchain/check/testdata/operators/overloaded/fail_error_recovery.carbon
index f3cdce58b4ad..d2d4358780ab 100644
--- a/toolchain/check/testdata/operators/overloaded/fail_error_recovery.carbon
+++ b/toolchain/check/testdata/operators/overloaded/fail_error_recovery.carbon
@@ -20,9 +20,10 @@ fn F() {
 }
 
 fn G(n: i32) {
-  // CHECK:STDERR: fail_error_recovery.carbon:[[@LINE+3]]:7: error: name `undeclared` not found [NameNotFound]
+  // CHECK:STDERR: fail_error_recovery.carbon:[[@LINE+4]]:7: error: name `undeclared` not found [NameNotFound]
   // CHECK:STDERR:   n + undeclared;
   // CHECK:STDERR:       ^~~~~~~~~~
+  // CHECK:STDERR:
   n + undeclared;
 }
 
diff --git a/toolchain/check/testdata/operators/overloaded/fail_no_impl.carbon b/toolchain/check/testdata/operators/overloaded/fail_no_impl.carbon
index e93fcf452491..d79cb154b5f5 100644
--- a/toolchain/check/testdata/operators/overloaded/fail_no_impl.carbon
+++ b/toolchain/check/testdata/operators/overloaded/fail_no_impl.carbon
@@ -35,9 +35,10 @@ fn TestRef(b: C) {
   // CHECK:STDERR:   ^~~~~~
   // CHECK:STDERR:
   a += b;
-  // CHECK:STDERR: fail_no_impl.carbon:[[@LINE+3]]:3: error: cannot access member of interface `Core.Inc` in type `C` that does not implement that interface [MissingImplInMemberAccess]
+  // CHECK:STDERR: fail_no_impl.carbon:[[@LINE+4]]:3: error: cannot access member of interface `Core.Inc` in type `C` that does not implement that interface [MissingImplInMemberAccess]
   // CHECK:STDERR:   ++a;
   // CHECK:STDERR:   ^~~
+  // CHECK:STDERR:
   ++a;
 }
 
@@ -146,7 +147,7 @@ fn TestRef(b: C) {
 // CHECK:STDOUT:   assign %a.var, %.loc32_16
 // CHECK:STDOUT:   %a.ref.loc37: ref %C = name_ref a, %a
 // CHECK:STDOUT:   %b.ref: %C = name_ref b, %b
-// CHECK:STDOUT:   %a.ref.loc41: ref %C = name_ref a, %a
+// CHECK:STDOUT:   %a.ref.loc42: ref %C = name_ref a, %a
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/operators/overloaded/fail_no_impl_for_arg.carbon b/toolchain/check/testdata/operators/overloaded/fail_no_impl_for_arg.carbon
index 901ee85a6047..828f0c4710e0 100644
--- a/toolchain/check/testdata/operators/overloaded/fail_no_impl_for_arg.carbon
+++ b/toolchain/check/testdata/operators/overloaded/fail_no_impl_for_arg.carbon
@@ -36,15 +36,16 @@ fn Test(a: C, b: D) -> C {
 
 fn TestAssign(b: D) {
   var a: C = {};
-  // CHECK:STDERR: fail_no_impl_for_arg.carbon:[[@LINE+9]]:8: error: cannot implicitly convert from `D` to `C` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_no_impl_for_arg.carbon:[[@LINE+10]]:8: error: cannot implicitly convert from `D` to `C` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   a += b;
   // CHECK:STDERR:        ^
-  // CHECK:STDERR: fail_no_impl_for_arg.carbon:[[@LINE+6]]:8: note: type `D` does not implement interface `Core.ImplicitAs(C)` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR: fail_no_impl_for_arg.carbon:[[@LINE+7]]:8: note: type `D` does not implement interface `Core.ImplicitAs(C)` [MissingImplInMemberAccessNote]
   // CHECK:STDERR:   a += b;
   // CHECK:STDERR:        ^
   // CHECK:STDERR: fail_no_impl_for_arg.carbon:[[@LINE-25]]:24: note: initializing function parameter [InCallToFunctionParam]
   // CHECK:STDERR:   fn Op[addr self: C*](other: C);
   // CHECK:STDERR:                        ^~~~~~~~
+  // CHECK:STDERR:
   a += b;
 }
 
@@ -225,7 +226,7 @@ fn TestAssign(b: D) {
 // CHECK:STDOUT:   %impl.elem0: %Op.type.421 = impl_witness_access constants.%impl_witness.95d, element0 [template = constants.%Op.d8e]
 // CHECK:STDOUT:   %Op.bound: <bound method> = bound_method %a.ref, %impl.elem0
 // CHECK:STDOUT:   %addr: %ptr.019 = addr_of %a.ref
-// CHECK:STDOUT:   %.loc48: %C = converted %b.ref, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc49: %C = converted %b.ref, <error> [template = <error>]
 // CHECK:STDOUT:   %Op.call: init %empty_tuple.type = call %Op.bound(%addr, <error>)
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/operators/overloaded/index.carbon b/toolchain/check/testdata/operators/overloaded/index.carbon
index 69ae40aa6b7c..573c14bf639f 100644
--- a/toolchain/check/testdata/operators/overloaded/index.carbon
+++ b/toolchain/check/testdata/operators/overloaded/index.carbon
@@ -70,9 +70,10 @@ library "[[@TEST_NAME]]";
 class C { }
 
 let c: C = {};
-// CHECK:STDERR: fail_index_with_not_implemented.carbon:[[@LINE+3]]:14: error: type `C` does not support indexing [TypeNotIndexable]
+// CHECK:STDERR: fail_index_with_not_implemented.carbon:[[@LINE+4]]:14: error: type `C` does not support indexing [TypeNotIndexable]
 // CHECK:STDERR: let x: i32 = c[0];
 // CHECK:STDERR:              ^~~~
+// CHECK:STDERR:
 let x: i32 = c[0];
 
 
diff --git a/toolchain/check/testdata/operators/overloaded/no_prelude/index.carbon b/toolchain/check/testdata/operators/overloaded/no_prelude/index.carbon
index ed7af649caea..730fbdf62c5a 100644
--- a/toolchain/check/testdata/operators/overloaded/no_prelude/index.carbon
+++ b/toolchain/check/testdata/operators/overloaded/no_prelude/index.carbon
@@ -24,13 +24,14 @@ fn F() { 0[1]; }
 
 library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_missing_index_with.carbon:[[@LINE+7]]:10: error: `Core.IndexWith` implicitly referenced here, but package `Core` not found [CoreNotFound]
+// CHECK:STDERR: fail_missing_index_with.carbon:[[@LINE+8]]:10: error: `Core.IndexWith` implicitly referenced here, but package `Core` not found [CoreNotFound]
 // CHECK:STDERR: fn F() { 0[1]; }
 // CHECK:STDERR:          ^~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_missing_index_with.carbon:[[@LINE+3]]:10: error: type `Core.IntLiteral` does not support indexing [TypeNotIndexable]
+// CHECK:STDERR: fail_missing_index_with.carbon:[[@LINE+4]]:10: error: type `Core.IntLiteral` does not support indexing [TypeNotIndexable]
 // CHECK:STDERR: fn F() { 0[1]; }
 // CHECK:STDERR:          ^~~~
+// CHECK:STDERR:
 fn F() { 0[1]; }
 
 // --- wrong_arg_count.carbon
diff --git a/toolchain/check/testdata/operators/overloaded/ordered.carbon b/toolchain/check/testdata/operators/overloaded/ordered.carbon
index e4e38b0a9e08..21eba8658196 100644
--- a/toolchain/check/testdata/operators/overloaded/ordered.carbon
+++ b/toolchain/check/testdata/operators/overloaded/ordered.carbon
@@ -68,9 +68,10 @@ fn TestGreater(a: D, b: D) -> bool {
 }
 
 fn TestGreaterEqual(a: D, b: D) -> bool {
-  // CHECK:STDERR: fail_no_impl.carbon:[[@LINE+3]]:10: error: cannot access member of interface `Core.Ordered` in type `D` that does not implement that interface [MissingImplInMemberAccess]
+  // CHECK:STDERR: fail_no_impl.carbon:[[@LINE+4]]:10: error: cannot access member of interface `Core.Ordered` in type `D` that does not implement that interface [MissingImplInMemberAccess]
   // CHECK:STDERR:   return a >= b;
   // CHECK:STDERR:          ^~~~~~
+  // CHECK:STDERR:
   return a >= b;
 }
 
diff --git a/toolchain/check/testdata/package_expr/fail_not_found.carbon b/toolchain/check/testdata/package_expr/fail_not_found.carbon
index e379190c621c..4a0edc8bd503 100644
--- a/toolchain/check/testdata/package_expr/fail_not_found.carbon
+++ b/toolchain/check/testdata/package_expr/fail_not_found.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/package_expr/fail_not_found.carbon
 
 fn Main() {
-  // CHECK:STDERR: fail_not_found.carbon:[[@LINE+3]]:16: error: member name `x` not found in `package` [MemberNameNotFoundInScope]
+  // CHECK:STDERR: fail_not_found.carbon:[[@LINE+4]]:16: error: member name `x` not found in `package` [MemberNameNotFoundInScope]
   // CHECK:STDERR:   var y: i32 = package.x;
   // CHECK:STDERR:                ^~~~~~~~~
+  // CHECK:STDERR:
   var y: i32 = package.x;
 }
 
diff --git a/toolchain/check/testdata/packages/fail_api_not_found.carbon b/toolchain/check/testdata/packages/fail_api_not_found.carbon
index 1d91169ffe34..d29ba279514a 100644
--- a/toolchain/check/testdata/packages/fail_api_not_found.carbon
+++ b/toolchain/check/testdata/packages/fail_api_not_found.carbon
@@ -26,9 +26,10 @@ impl package Foo library "[[@TEST_NAME]]";
 
 // --- fail_no_api_main_lib.impl.carbon
 
-// CHECK:STDERR: fail_no_api_main_lib.impl.carbon:[[@LINE+3]]:6: error: corresponding API for 'Main//no_api_main_lib' not found [LibraryApiNotFound]
+// CHECK:STDERR: fail_no_api_main_lib.impl.carbon:[[@LINE+4]]:6: error: corresponding API for 'Main//no_api_main_lib' not found [LibraryApiNotFound]
 // CHECK:STDERR: impl library "no_api_main_lib";
 // CHECK:STDERR:      ^~~~~~~
+// CHECK:STDERR:
 impl library "[[@TEST_NAME]]";
 
 // CHECK:STDOUT: --- fail_no_api.impl.carbon
diff --git a/toolchain/check/testdata/packages/fail_conflict_no_namespaces.carbon b/toolchain/check/testdata/packages/fail_conflict_no_namespaces.carbon
index 844d752c3227..9d2f37ae46b5 100644
--- a/toolchain/check/testdata/packages/fail_conflict_no_namespaces.carbon
+++ b/toolchain/check/testdata/packages/fail_conflict_no_namespaces.carbon
@@ -24,14 +24,15 @@ var Foo: i32;
 
 package Example library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_conflict.carbon:[[@LINE+8]]:1: in import [InImport]
+// CHECK:STDERR: fail_conflict.carbon:[[@LINE+9]]:1: in import [InImport]
 // CHECK:STDERR: var.carbon:4:5: error: duplicate name being declared in the same scope [NameDeclDuplicate]
 // CHECK:STDERR: var Foo: i32;
 // CHECK:STDERR:     ^~~
-// CHECK:STDERR: fail_conflict.carbon:[[@LINE+4]]:1: in import [InImport]
+// CHECK:STDERR: fail_conflict.carbon:[[@LINE+5]]:1: in import [InImport]
 // CHECK:STDERR: fn.carbon:4:1: note: name is previously declared here [NameDeclPrevious]
 // CHECK:STDERR: fn Foo();
 // CHECK:STDERR: ^~~~~~~~~
+// CHECK:STDERR:
 import library "fn";
 import library "var";
 
diff --git a/toolchain/check/testdata/packages/fail_cycle.carbon b/toolchain/check/testdata/packages/fail_cycle.carbon
index abe2a41511cf..910bfbb1d98f 100644
--- a/toolchain/check/testdata/packages/fail_cycle.carbon
+++ b/toolchain/check/testdata/packages/fail_cycle.carbon
@@ -50,9 +50,10 @@ impl package C;
 
 package CycleChild;
 
-// CHECK:STDERR: fail_cycle_child.carbon:[[@LINE+3]]:1: error: import cannot be used due to a cycle; cycle must be fixed to import [ImportCycleDetected]
+// CHECK:STDERR: fail_cycle_child.carbon:[[@LINE+4]]:1: error: import cannot be used due to a cycle; cycle must be fixed to import [ImportCycleDetected]
 // CHECK:STDERR: import B;
 // CHECK:STDERR: ^~~~~~
+// CHECK:STDERR:
 import B;
 
 // CHECK:STDOUT: --- fail_a.carbon
diff --git a/toolchain/check/testdata/packages/fail_duplicate_api.carbon b/toolchain/check/testdata/packages/fail_duplicate_api.carbon
index da19cec46950..3c4bd0f4453d 100644
--- a/toolchain/check/testdata/packages/fail_duplicate_api.carbon
+++ b/toolchain/check/testdata/packages/fail_duplicate_api.carbon
@@ -44,9 +44,10 @@ package Package library "lib";
 
 // --- fail_package_lib2.carbon
 
-// CHECK:STDERR: fail_package_lib2.carbon:[[@LINE+3]]:1: error: library's API previously provided by `package_lib1.carbon` [DuplicateLibraryApi]
+// CHECK:STDERR: fail_package_lib2.carbon:[[@LINE+4]]:1: error: library's API previously provided by `package_lib1.carbon` [DuplicateLibraryApi]
 // CHECK:STDERR: package Package library "lib";
 // CHECK:STDERR: ^~~~~~~
+// CHECK:STDERR:
 package Package library "lib";
 
 // CHECK:STDOUT: --- main1.carbon
diff --git a/toolchain/check/testdata/packages/fail_extension.carbon b/toolchain/check/testdata/packages/fail_extension.carbon
index 400aa6008539..ef799d6ab49a 100644
--- a/toolchain/check/testdata/packages/fail_extension.carbon
+++ b/toolchain/check/testdata/packages/fail_extension.carbon
@@ -78,9 +78,10 @@ package SwappedExt;
 
 // --- fail_swapped_ext.carbon
 
-// CHECK:STDERR: fail_swapped_ext.carbon:[[@LINE+3]]:6: error: file extension of `.impl.carbon` required for `impl` [IncorrectExtension]
+// CHECK:STDERR: fail_swapped_ext.carbon:[[@LINE+4]]:6: error: file extension of `.impl.carbon` required for `impl` [IncorrectExtension]
 // CHECK:STDERR: impl package SwappedExt;
 // CHECK:STDERR:      ^~~~~~~
+// CHECK:STDERR:
 impl package SwappedExt;
 
 
diff --git a/toolchain/check/testdata/packages/fail_import_default.carbon b/toolchain/check/testdata/packages/fail_import_default.carbon
index 6e76196ab86d..3e655e4d2b20 100644
--- a/toolchain/check/testdata/packages/fail_import_default.carbon
+++ b/toolchain/check/testdata/packages/fail_import_default.carbon
@@ -40,9 +40,10 @@ import library default;
 
 library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_main_lib_import_default.carbon:[[@LINE+3]]:1: error: cannot import `Main//default` [ImportMainDefaultLibrary]
+// CHECK:STDERR: fail_main_lib_import_default.carbon:[[@LINE+4]]:1: error: cannot import `Main//default` [ImportMainDefaultLibrary]
 // CHECK:STDERR: import library default;
 // CHECK:STDERR: ^~~~~~
+// CHECK:STDERR:
 import library default;
 
 // CHECK:STDOUT: --- fail_default_api.carbon
diff --git a/toolchain/check/testdata/packages/fail_import_invalid.carbon b/toolchain/check/testdata/packages/fail_import_invalid.carbon
index 430e14d10cd4..16f7a519df76 100644
--- a/toolchain/check/testdata/packages/fail_import_invalid.carbon
+++ b/toolchain/check/testdata/packages/fail_import_invalid.carbon
@@ -89,9 +89,10 @@ import Implicit library "implicit_lib";
 // --- fail_not_found.carbon
 package NotFound;
 
-// CHECK:STDERR: fail_not_found.carbon:[[@LINE+3]]:1: error: imported API 'ImportNotFound' not found [ImportNotFound]
+// CHECK:STDERR: fail_not_found.carbon:[[@LINE+4]]:1: error: imported API 'ImportNotFound' not found [ImportNotFound]
 // CHECK:STDERR: import ImportNotFound;
 // CHECK:STDERR: ^~~~~~
+// CHECK:STDERR:
 import ImportNotFound;
 
 // CHECK:STDOUT: --- fail_main.carbon
diff --git a/toolchain/check/testdata/packages/fail_import_repeat.carbon b/toolchain/check/testdata/packages/fail_import_repeat.carbon
index 2fb567ed1fc8..52e839066bc9 100644
--- a/toolchain/check/testdata/packages/fail_import_repeat.carbon
+++ b/toolchain/check/testdata/packages/fail_import_repeat.carbon
@@ -57,12 +57,13 @@ import library "main_lib";
 package Api library "[[@TEST_NAME]]";
 
 import library default;
-// CHECK:STDERR: fail_default_import.carbon:[[@LINE+6]]:1: error: library imported more than once [RepeatedImport]
+// CHECK:STDERR: fail_default_import.carbon:[[@LINE+7]]:1: error: library imported more than once [RepeatedImport]
 // CHECK:STDERR: import library default;
 // CHECK:STDERR: ^~~~~~
 // CHECK:STDERR: fail_default_import.carbon:[[@LINE-4]]:1: note: first import here [FirstImported]
 // CHECK:STDERR: import library default;
 // CHECK:STDERR: ^~~~~~
+// CHECK:STDERR:
 import library default;
 
 // CHECK:STDOUT: --- api.carbon
diff --git a/toolchain/check/testdata/packages/fail_import_type_error.carbon b/toolchain/check/testdata/packages/fail_import_type_error.carbon
index 2234b3d2d675..152f3dffa70f 100644
--- a/toolchain/check/testdata/packages/fail_import_type_error.carbon
+++ b/toolchain/check/testdata/packages/fail_import_type_error.carbon
@@ -27,9 +27,10 @@ var b_ref: {.a = x};
 // CHECK:STDERR:             ^
 // CHECK:STDERR:
 var c_ref: (x,);
-// CHECK:STDERR: fail_implicit.carbon:[[@LINE+3]]:12: error: name `x` not found [NameNotFound]
+// CHECK:STDERR: fail_implicit.carbon:[[@LINE+4]]:12: error: name `x` not found [NameNotFound]
 // CHECK:STDERR: var d_ref: x*;
 // CHECK:STDERR:            ^
+// CHECK:STDERR:
 var d_ref: x*;
 
 // --- implicit.impl.carbon
diff --git a/toolchain/check/testdata/packages/fail_name_with_import_failure.carbon b/toolchain/check/testdata/packages/fail_name_with_import_failure.carbon
index 08bb03e9f6d4..7b0eba2e4466 100644
--- a/toolchain/check/testdata/packages/fail_name_with_import_failure.carbon
+++ b/toolchain/check/testdata/packages/fail_name_with_import_failure.carbon
@@ -10,9 +10,10 @@
 
 // --- fail_implicit.impl.carbon
 
-// CHECK:STDERR: fail_implicit.impl.carbon:[[@LINE+3]]:6: error: corresponding API for 'Implicit' not found [LibraryApiNotFound]
+// CHECK:STDERR: fail_implicit.impl.carbon:[[@LINE+4]]:6: error: corresponding API for 'Implicit' not found [LibraryApiNotFound]
 // CHECK:STDERR: impl package Implicit;
 // CHECK:STDERR:      ^~~~~~~
+// CHECK:STDERR:
 impl package Implicit;
 
 var a: () = A();
diff --git a/toolchain/check/testdata/packages/no_prelude/cross_package_export.carbon b/toolchain/check/testdata/packages/no_prelude/cross_package_export.carbon
index fe3f724ae568..19b4169f7a9d 100644
--- a/toolchain/check/testdata/packages/no_prelude/cross_package_export.carbon
+++ b/toolchain/check/testdata/packages/no_prelude/cross_package_export.carbon
@@ -186,9 +186,10 @@ library "[[@TEST_NAME]]";
 import Other library "export_name";
 import Other library "conflict";
 
-// CHECK:STDERR: fail_conflict_on_export_name.carbon:[[@LINE+3]]:11: note: in name lookup for `C` [InNameLookup]
+// CHECK:STDERR: fail_conflict_on_export_name.carbon:[[@LINE+4]]:11: note: in name lookup for `C` [InNameLookup]
 // CHECK:STDERR: alias C = Other.C;
 // CHECK:STDERR:           ^~~~~~~
+// CHECK:STDERR:
 alias C = Other.C;
 
 // CHECK:STDOUT: --- base.carbon
diff --git a/toolchain/check/testdata/packages/no_prelude/cross_package_import.carbon b/toolchain/check/testdata/packages/no_prelude/cross_package_import.carbon
index 285c1cd2b597..fb15256ebe7d 100644
--- a/toolchain/check/testdata/packages/no_prelude/cross_package_import.carbon
+++ b/toolchain/check/testdata/packages/no_prelude/cross_package_import.carbon
@@ -201,9 +201,10 @@ library "[[@TEST_NAME]]";
 
 import Other library "other_fn_use";
 
-// CHECK:STDERR: fail_use_other_fn_use.carbon:[[@LINE+3]]:13: error: member name `F` not found in `Other` [MemberNameNotFoundInScope]
+// CHECK:STDERR: fail_use_other_fn_use.carbon:[[@LINE+4]]:13: error: member name `F` not found in `Other` [MemberNameNotFoundInScope]
 // CHECK:STDERR: fn UseF() { Other.F(); }
 // CHECK:STDERR:             ^~~~~~~
+// CHECK:STDERR:
 fn UseF() { Other.F(); }
 
 // CHECK:STDOUT: --- other_fn.carbon
diff --git a/toolchain/check/testdata/packages/no_prelude/export_import.carbon b/toolchain/check/testdata/packages/no_prelude/export_import.carbon
index 9a68d54e70fc..1acf11e46796 100644
--- a/toolchain/check/testdata/packages/no_prelude/export_import.carbon
+++ b/toolchain/check/testdata/packages/no_prelude/export_import.carbon
@@ -148,9 +148,10 @@ library "[[@TEST_NAME]]";
 
 import library "non_export";
 
-// CHECK:STDERR: fail_use_non_export.carbon:[[@LINE+3]]:15: error: name `C` not found [NameNotFound]
+// CHECK:STDERR: fail_use_non_export.carbon:[[@LINE+4]]:15: error: name `C` not found [NameNotFound]
 // CHECK:STDERR: alias Local = C;
 // CHECK:STDERR:               ^
+// CHECK:STDERR:
 alias Local = C;
 
 // --- use_non_export_then_base.carbon
diff --git a/toolchain/check/testdata/packages/no_prelude/export_mixed.carbon b/toolchain/check/testdata/packages/no_prelude/export_mixed.carbon
index 1859645e7264..795cfe4f3ba4 100644
--- a/toolchain/check/testdata/packages/no_prelude/export_mixed.carbon
+++ b/toolchain/check/testdata/packages/no_prelude/export_mixed.carbon
@@ -88,9 +88,10 @@ library "[[@TEST_NAME]]";
 import library "export_import_then_name";
 import library "export_name_then_import";
 
-// CHECK:STDERR: fail_nonexport_use_both.carbon:[[@LINE+3]]:8: error: name `D` not found [NameNotFound]
+// CHECK:STDERR: fail_nonexport_use_both.carbon:[[@LINE+4]]:8: error: name `D` not found [NameNotFound]
 // CHECK:STDERR: var d: D = {.y = ()};
 // CHECK:STDERR:        ^
+// CHECK:STDERR:
 var d: D = {.y = ()};
 
 // --- use_both_reversed.carbon
@@ -384,8 +385,8 @@ var d: D = {.y = ()};
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %.loc10_19: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:   %.loc10_20: %struct_type.y = struct_literal (%.loc10_19)
+// CHECK:STDOUT:   %.loc11_19: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:   %.loc11_20: %struct_type.y = struct_literal (%.loc11_19)
 // CHECK:STDOUT:   assign file.%d.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/packages/no_prelude/export_name.carbon b/toolchain/check/testdata/packages/no_prelude/export_name.carbon
index b334ef2a1edd..1eeb733a4812 100644
--- a/toolchain/check/testdata/packages/no_prelude/export_name.carbon
+++ b/toolchain/check/testdata/packages/no_prelude/export_name.carbon
@@ -195,9 +195,10 @@ library "[[@TEST_NAME]]";
 
 import library "base";
 
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+3]]:1: error: `private` not allowed on `export` declaration [ModifierNotAllowedOnDeclaration]
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+4]]:1: error: `private` not allowed on `export` declaration [ModifierNotAllowedOnDeclaration]
 // CHECK:STDERR: private export C;
 // CHECK:STDERR: ^~~~~~~
+// CHECK:STDERR:
 private export C;
 
 // CHECK:STDOUT: --- base.carbon
diff --git a/toolchain/check/testdata/packages/no_prelude/fail_export_name_member.carbon b/toolchain/check/testdata/packages/no_prelude/fail_export_name_member.carbon
index 0c912103fc3d..7061dfb2467d 100644
--- a/toolchain/check/testdata/packages/no_prelude/fail_export_name_member.carbon
+++ b/toolchain/check/testdata/packages/no_prelude/fail_export_name_member.carbon
@@ -24,13 +24,14 @@ import library "a";
 
 // TODO: This diagnostic doesn't clearly explain the problem. We should instead
 // say something like: Only namespace-scope names can be exported.
-// CHECK:STDERR: fail_b.carbon:[[@LINE+7]]:8: error: name qualifiers are only allowed for entities that provide a scope [QualifiedNameInNonScope]
+// CHECK:STDERR: fail_b.carbon:[[@LINE+8]]:8: error: name qualifiers are only allowed for entities that provide a scope [QualifiedNameInNonScope]
 // CHECK:STDERR: export C.n;
 // CHECK:STDERR:        ^
 // CHECK:STDERR: fail_b.carbon:[[@LINE-7]]:1: in import [InImport]
 // CHECK:STDERR: a.carbon:4:1: note: referenced non-scope entity declared here [QualifiedNameNonScopeEntity]
 // CHECK:STDERR: class C {
 // CHECK:STDERR: ^~~~~~~~~
+// CHECK:STDERR:
 export C.n;
 
 // CHECK:STDOUT: --- a.carbon
diff --git a/toolchain/check/testdata/packages/no_prelude/fail_export_name_params.carbon b/toolchain/check/testdata/packages/no_prelude/fail_export_name_params.carbon
index 9f30016e2f6c..195804a01541 100644
--- a/toolchain/check/testdata/packages/no_prelude/fail_export_name_params.carbon
+++ b/toolchain/check/testdata/packages/no_prelude/fail_export_name_params.carbon
@@ -23,9 +23,10 @@ import library "a";
 
 export C1;
 
-// CHECK:STDERR: fail_b.carbon:[[@LINE+3]]:10: error: `export` declaration cannot have parameters [UnexpectedDeclNameParams]
+// CHECK:STDERR: fail_b.carbon:[[@LINE+4]]:10: error: `export` declaration cannot have parameters [UnexpectedDeclNameParams]
 // CHECK:STDERR: export C2(T:! type);
 // CHECK:STDERR:          ^~~~~~~~~~
+// CHECK:STDERR:
 export C2(T:! type);
 
 // CHECK:STDOUT: --- a.carbon
diff --git a/toolchain/check/testdata/packages/no_prelude/fail_modifiers.carbon b/toolchain/check/testdata/packages/no_prelude/fail_modifiers.carbon
index a069d2c40efa..7487309c25b2 100644
--- a/toolchain/check/testdata/packages/no_prelude/fail_modifiers.carbon
+++ b/toolchain/check/testdata/packages/no_prelude/fail_modifiers.carbon
@@ -90,13 +90,14 @@ virtual import VirtualImport;
 // CHECK:STDERR:
 base import BaseImport;
 
-// CHECK:STDERR: fail_import_modifiers.carbon:[[@LINE+7]]:9: error: imported API 'PrivateImport' not found [ImportNotFound]
+// CHECK:STDERR: fail_import_modifiers.carbon:[[@LINE+8]]:9: error: imported API 'PrivateImport' not found [ImportNotFound]
 // CHECK:STDERR: private import PrivateImport;
 // CHECK:STDERR:         ^~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_import_modifiers.carbon:[[@LINE+3]]:1: error: `private` not allowed on `import` declaration [ModifierNotAllowedOnDeclaration]
+// CHECK:STDERR: fail_import_modifiers.carbon:[[@LINE+4]]:1: error: `private` not allowed on `import` declaration [ModifierNotAllowedOnDeclaration]
 // CHECK:STDERR: private import PrivateImport;
 // CHECK:STDERR: ^~~~~~~
+// CHECK:STDERR:
 private import PrivateImport;
 
 // CHECK:STDOUT: --- fail_export_package.carbon
diff --git a/toolchain/check/testdata/packages/no_prelude/implicit_imports_entities.carbon b/toolchain/check/testdata/packages/no_prelude/implicit_imports_entities.carbon
index adc9f0cc92ac..2d6fe65f8872 100644
--- a/toolchain/check/testdata/packages/no_prelude/implicit_imports_entities.carbon
+++ b/toolchain/check/testdata/packages/no_prelude/implicit_imports_entities.carbon
@@ -154,7 +154,7 @@ import library "local_other";
 
 impl library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_import_conflict_reverse.impl.carbon:[[@LINE+8]]:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
+// CHECK:STDERR: fail_import_conflict_reverse.impl.carbon:[[@LINE+9]]:1: error: duplicate name being declared in the same scope [NameDeclDuplicate]
 // CHECK:STDERR: import Other library "o1";
 // CHECK:STDERR: ^~~~~~
 // CHECK:STDERR: fail_import_conflict_reverse.impl.carbon:[[@LINE-5]]:6: in import [InImport]
@@ -162,6 +162,7 @@ impl library "[[@TEST_NAME]]";
 // CHECK:STDERR: local_other.carbon:4:1: note: name is previously declared here [NameDeclPrevious]
 // CHECK:STDERR: class Other {}
 // CHECK:STDERR: ^~~~~~~~~~~~~
+// CHECK:STDERR:
 import Other library "o1";
 
 // CHECK:STDOUT: --- c1.carbon
diff --git a/toolchain/check/testdata/packages/no_prelude/missing_prelude.carbon b/toolchain/check/testdata/packages/no_prelude/missing_prelude.carbon
index 37410b783eb2..e63233937b79 100644
--- a/toolchain/check/testdata/packages/no_prelude/missing_prelude.carbon
+++ b/toolchain/check/testdata/packages/no_prelude/missing_prelude.carbon
@@ -80,9 +80,10 @@ class Core {
   fn Int[T:! type](N:! T) -> {} { return {}; }
 }
 
-// CHECK:STDERR: fail_prelude_as_class.carbon:[[@LINE+3]]:13: error: `Core.Int` implicitly referenced here, but package `Core` not found [CoreNotFound]
+// CHECK:STDERR: fail_prelude_as_class.carbon:[[@LINE+4]]:13: error: `Core.Int` implicitly referenced here, but package `Core` not found [CoreNotFound]
 // CHECK:STDERR: var n: {} = i32;
 // CHECK:STDERR:             ^~~
+// CHECK:STDERR:
 var n: {} = i32;
 
 // CHECK:STDOUT: --- fail_missing_prelude.carbon
diff --git a/toolchain/check/testdata/packages/no_prelude/restricted_package_names.carbon b/toolchain/check/testdata/packages/no_prelude/restricted_package_names.carbon
index b6286957e80c..a7a9d87b7d42 100644
--- a/toolchain/check/testdata/packages/no_prelude/restricted_package_names.carbon
+++ b/toolchain/check/testdata/packages/no_prelude/restricted_package_names.carbon
@@ -82,9 +82,10 @@ package r#Cpp;
 
 // --- fail_cpp_lib.carbon
 
-// CHECK:STDERR: fail_cpp_lib.carbon:[[@LINE+3]]:1: error: `Cpp` cannot be used by a `package` declaration [CppPackageDeclaration]
+// CHECK:STDERR: fail_cpp_lib.carbon:[[@LINE+4]]:1: error: `Cpp` cannot be used by a `package` declaration [CppPackageDeclaration]
 // CHECK:STDERR: package Cpp library "cpp_lib";
 // CHECK:STDERR: ^~~~~~~
+// CHECK:STDERR:
 package Cpp library "[[@TEST_NAME]]";
 
 // CHECK:STDOUT: --- lowercase_main.carbon
diff --git a/toolchain/check/testdata/pointer/fail_address_of_error.carbon b/toolchain/check/testdata/pointer/fail_address_of_error.carbon
index a21209140f08..fe5c405f2732 100644
--- a/toolchain/check/testdata/pointer/fail_address_of_error.carbon
+++ b/toolchain/check/testdata/pointer/fail_address_of_error.carbon
@@ -14,13 +14,14 @@ fn Test() {
   // CHECK:STDERR:    ^~~~~~~~~~
   // CHECK:STDERR:
   &undeclared;
-  // CHECK:STDERR: fail_address_of_error.carbon:[[@LINE+7]]:6: error: name `undeclared` not found [NameNotFound]
+  // CHECK:STDERR: fail_address_of_error.carbon:[[@LINE+8]]:6: error: name `undeclared` not found [NameNotFound]
   // CHECK:STDERR:   &(&undeclared);
   // CHECK:STDERR:      ^~~~~~~~~~
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_address_of_error.carbon:[[@LINE+3]]:3: error: cannot take the address of non-reference expression [AddrOfNonRef]
+  // CHECK:STDERR: fail_address_of_error.carbon:[[@LINE+4]]:3: error: cannot take the address of non-reference expression [AddrOfNonRef]
   // CHECK:STDERR:   &(&undeclared);
   // CHECK:STDERR:   ^
+  // CHECK:STDERR:
   &(&undeclared);
 }
 
@@ -51,9 +52,9 @@ fn Test() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %undeclared.ref.loc16: <error> = name_ref undeclared, <error> [template = <error>]
 // CHECK:STDOUT:   %addr.loc16: <error> = addr_of %undeclared.ref.loc16 [template = <error>]
-// CHECK:STDOUT:   %undeclared.ref.loc24: <error> = name_ref undeclared, <error> [template = <error>]
-// CHECK:STDOUT:   %addr.loc24_5: <error> = addr_of %undeclared.ref.loc24 [template = <error>]
-// CHECK:STDOUT:   %addr.loc24_3: <error> = addr_of <error> [template = <error>]
+// CHECK:STDOUT:   %undeclared.ref.loc25: <error> = name_ref undeclared, <error> [template = <error>]
+// CHECK:STDOUT:   %addr.loc25_5: <error> = addr_of %undeclared.ref.loc25 [template = <error>]
+// CHECK:STDOUT:   %addr.loc25_3: <error> = addr_of <error> [template = <error>]
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/pointer/fail_address_of_value.carbon b/toolchain/check/testdata/pointer/fail_address_of_value.carbon
index c99b905b2d46..003f7764dcb1 100644
--- a/toolchain/check/testdata/pointer/fail_address_of_value.carbon
+++ b/toolchain/check/testdata/pointer/fail_address_of_value.carbon
@@ -93,9 +93,10 @@ fn AddressOfTupleElementValue() {
 }
 
 fn AddressOfParam(param: i32) {
-  // CHECK:STDERR: fail_address_of_value.carbon:[[@LINE+3]]:26: error: cannot take the address of non-reference expression [AddrOfNonRef]
+  // CHECK:STDERR: fail_address_of_value.carbon:[[@LINE+4]]:26: error: cannot take the address of non-reference expression [AddrOfNonRef]
   // CHECK:STDERR:   var param_addr: i32* = &param;
   // CHECK:STDERR:                          ^
+  // CHECK:STDERR:
   var param_addr: i32* = &param;
 }
 
diff --git a/toolchain/check/testdata/pointer/fail_deref_error.carbon b/toolchain/check/testdata/pointer/fail_deref_error.carbon
index 31473a4c01cd..eb729017bd1f 100644
--- a/toolchain/check/testdata/pointer/fail_deref_error.carbon
+++ b/toolchain/check/testdata/pointer/fail_deref_error.carbon
@@ -13,9 +13,10 @@
 // CHECK:STDERR:               ^~~~~~~~~~
 // CHECK:STDERR:
 let n: i32 = *undeclared;
-// CHECK:STDERR: fail_deref_error.carbon:[[@LINE+3]]:15: error: name `undeclared` not found [NameNotFound]
+// CHECK:STDERR: fail_deref_error.carbon:[[@LINE+4]]:15: error: name `undeclared` not found [NameNotFound]
 // CHECK:STDERR: let n2: i32 = undeclared->foo;
 // CHECK:STDERR:               ^~~~~~~~~~
+// CHECK:STDERR:
 let n2: i32 = undeclared->foo;
 
 // CHECK:STDOUT: --- fail_deref_error.carbon
@@ -47,8 +48,8 @@ let n2: i32 = undeclared->foo;
 // CHECK:STDOUT:   %undeclared.ref.loc15: <error> = name_ref undeclared, <error> [template = <error>]
 // CHECK:STDOUT:   %.loc15: ref <error> = deref <error>
 // CHECK:STDOUT:   %n: %i32 = bind_name n, <error>
-// CHECK:STDOUT:   %undeclared.ref.loc19: <error> = name_ref undeclared, <error> [template = <error>]
-// CHECK:STDOUT:   %.loc19: ref <error> = deref <error>
+// CHECK:STDOUT:   %undeclared.ref.loc20: <error> = name_ref undeclared, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc20: ref <error> = deref <error>
 // CHECK:STDOUT:   %foo.ref: <error> = name_ref foo, <error> [template = <error>]
 // CHECK:STDOUT:   %n2: %i32 = bind_name n2, <error>
 // CHECK:STDOUT:   return
diff --git a/toolchain/check/testdata/pointer/fail_deref_function.carbon b/toolchain/check/testdata/pointer/fail_deref_function.carbon
index e5581afc0b75..7d8149dc00d2 100644
--- a/toolchain/check/testdata/pointer/fail_deref_function.carbon
+++ b/toolchain/check/testdata/pointer/fail_deref_function.carbon
@@ -14,9 +14,10 @@ fn A() {
   // CHECK:STDERR:    ^
   // CHECK:STDERR:
   *A;
-  // CHECK:STDERR: fail_deref_function.carbon:[[@LINE+3]]:3: error: expression cannot be used as a value [UseOfNonExprAsValue]
+  // CHECK:STDERR: fail_deref_function.carbon:[[@LINE+4]]:3: error: expression cannot be used as a value [UseOfNonExprAsValue]
   // CHECK:STDERR:   A->foo;
   // CHECK:STDERR:   ^
+  // CHECK:STDERR:
   A->foo;
 }
 
@@ -47,8 +48,8 @@ fn A() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %A.ref.loc16: %A.type = name_ref A, file.%A.decl [template = constants.%A]
 // CHECK:STDOUT:   %.loc16: ref <error> = deref <error>
-// CHECK:STDOUT:   %A.ref.loc20: %A.type = name_ref A, file.%A.decl [template = constants.%A]
-// CHECK:STDOUT:   %.loc20: ref <error> = deref <error>
+// CHECK:STDOUT:   %A.ref.loc21: %A.type = name_ref A, file.%A.decl [template = constants.%A]
+// CHECK:STDOUT:   %.loc21: ref <error> = deref <error>
 // CHECK:STDOUT:   %foo.ref: <error> = name_ref foo, <error> [template = <error>]
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/pointer/fail_deref_namespace.carbon b/toolchain/check/testdata/pointer/fail_deref_namespace.carbon
index 70209f14436f..ebb69f15813c 100644
--- a/toolchain/check/testdata/pointer/fail_deref_namespace.carbon
+++ b/toolchain/check/testdata/pointer/fail_deref_namespace.carbon
@@ -16,9 +16,10 @@ fn F() {
   // CHECK:STDERR:    ^
   // CHECK:STDERR:
   *A;
-  // CHECK:STDERR: fail_deref_namespace.carbon:[[@LINE+3]]:3: error: expression cannot be used as a value [UseOfNonExprAsValue]
+  // CHECK:STDERR: fail_deref_namespace.carbon:[[@LINE+4]]:3: error: expression cannot be used as a value [UseOfNonExprAsValue]
   // CHECK:STDERR:   A->foo;
   // CHECK:STDERR:   ^
+  // CHECK:STDERR:
   A->foo;
 }
 
@@ -51,8 +52,8 @@ fn F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %A.ref.loc18: <namespace> = name_ref A, file.%A [template = file.%A]
 // CHECK:STDOUT:   %.loc18: ref <error> = deref <error>
-// CHECK:STDOUT:   %A.ref.loc22: <namespace> = name_ref A, file.%A [template = file.%A]
-// CHECK:STDOUT:   %.loc22: ref <error> = deref <error>
+// CHECK:STDOUT:   %A.ref.loc23: <namespace> = name_ref A, file.%A [template = file.%A]
+// CHECK:STDOUT:   %.loc23: ref <error> = deref <error>
 // CHECK:STDOUT:   %foo.ref: <error> = name_ref foo, <error> [template = <error>]
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/pointer/fail_deref_not_pointer.carbon b/toolchain/check/testdata/pointer/fail_deref_not_pointer.carbon
index 0d78d003e1e0..38c6f51e06ee 100644
--- a/toolchain/check/testdata/pointer/fail_deref_not_pointer.carbon
+++ b/toolchain/check/testdata/pointer/fail_deref_not_pointer.carbon
@@ -34,9 +34,10 @@ fn Deref(n: i32) {
   // CHECK:STDERR:   ^
   // CHECK:STDERR:
   *{};
-  // CHECK:STDERR: fail_deref_not_pointer.carbon:[[@LINE+3]]:5: error: cannot apply `->` operator to non-pointer type `{}` [ArrowOperatorOfNonPointer]
+  // CHECK:STDERR: fail_deref_not_pointer.carbon:[[@LINE+4]]:5: error: cannot apply `->` operator to non-pointer type `{}` [ArrowOperatorOfNonPointer]
   // CHECK:STDERR:   {}->foo;
   // CHECK:STDERR:     ^~
+  // CHECK:STDERR:
   {}->foo;
 }
 
@@ -100,11 +101,11 @@ fn Deref(n: i32) {
 // CHECK:STDOUT:   %empty_struct.loc36: %empty_struct_type = struct_value () [template = constants.%empty_struct]
 // CHECK:STDOUT:   %.loc36_5.2: %empty_struct_type = converted %.loc36_5.1, %empty_struct.loc36 [template = constants.%empty_struct]
 // CHECK:STDOUT:   %.loc36_3: ref <error> = deref %.loc36_5.2
-// CHECK:STDOUT:   %.loc40_4.1: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:   %empty_struct.loc40: %empty_struct_type = struct_value () [template = constants.%empty_struct]
-// CHECK:STDOUT:   %.loc40_4.2: %empty_struct_type = converted %.loc40_4.1, %empty_struct.loc40 [template = constants.%empty_struct]
-// CHECK:STDOUT:   %.loc40_5: ref <error> = deref %.loc40_4.2
-// CHECK:STDOUT:   %foo.ref.loc40: <error> = name_ref foo, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc41_4.1: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %empty_struct.loc41: %empty_struct_type = struct_value () [template = constants.%empty_struct]
+// CHECK:STDOUT:   %.loc41_4.2: %empty_struct_type = converted %.loc41_4.1, %empty_struct.loc41 [template = constants.%empty_struct]
+// CHECK:STDOUT:   %.loc41_5: ref <error> = deref %.loc41_4.2
+// CHECK:STDOUT:   %foo.ref.loc41: <error> = name_ref foo, <error> [template = <error>]
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/pointer/fail_deref_type.carbon b/toolchain/check/testdata/pointer/fail_deref_type.carbon
index 7ad5b4df857f..4eed4031172d 100644
--- a/toolchain/check/testdata/pointer/fail_deref_type.carbon
+++ b/toolchain/check/testdata/pointer/fail_deref_type.carbon
@@ -16,9 +16,10 @@
 // CHECK:STDERR:        ^
 // CHECK:STDERR:
 var p: *i32;
-// CHECK:STDERR: fail_deref_type.carbon:[[@LINE+3]]:12: error: cannot apply `->` operator to non-pointer type `type` [ArrowOperatorOfNonPointer]
+// CHECK:STDERR: fail_deref_type.carbon:[[@LINE+4]]:12: error: cannot apply `->` operator to non-pointer type `type` [ArrowOperatorOfNonPointer]
 // CHECK:STDERR: var p2: i32->foo;
 // CHECK:STDERR:            ^~
+// CHECK:STDERR:
 var p2: i32->foo;
 
 // CHECK:STDOUT: --- fail_deref_type.carbon
diff --git a/toolchain/check/testdata/pointer/fail_type_mismatch.carbon b/toolchain/check/testdata/pointer/fail_type_mismatch.carbon
index c81f6f0a8f6b..7a6b001ebb28 100644
--- a/toolchain/check/testdata/pointer/fail_type_mismatch.carbon
+++ b/toolchain/check/testdata/pointer/fail_type_mismatch.carbon
@@ -9,12 +9,13 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/pointer/fail_type_mismatch.carbon
 
 fn ConstMismatch(p: const {}*) -> const ({}*) {
-  // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+6]]:3: error: cannot implicitly convert from `const {}*` to `const ({}*)` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+7]]:3: error: cannot implicitly convert from `const {}*` to `const ({}*)` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   return p;
   // CHECK:STDERR:   ^~~~~~~~~
-  // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+3]]:3: note: type `const {}*` does not implement interface `Core.ImplicitAs(const ({}*))` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+4]]:3: note: type `const {}*` does not implement interface `Core.ImplicitAs(const ({}*))` [MissingImplInMemberAccessNote]
   // CHECK:STDERR:   return p;
   // CHECK:STDERR:   ^~~~~~~~~
+  // CHECK:STDERR:
   return p;
 }
 
@@ -70,7 +71,7 @@ fn ConstMismatch(p: const {}*) -> const ({}*) {
 // CHECK:STDOUT: fn @ConstMismatch(%p.param_patt: %ptr.bf9) -> %const.987 {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %p.ref: %ptr.bf9 = name_ref p, %p
-// CHECK:STDOUT:   %.loc18: %const.987 = converted %p.ref, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc19: %const.987 = converted %p.ref, <error> [template = <error>]
 // CHECK:STDOUT:   return <error>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/return/fail_call_in_type.carbon b/toolchain/check/testdata/return/fail_call_in_type.carbon
index 7efa416bae39..2849c0682ac2 100644
--- a/toolchain/check/testdata/return/fail_call_in_type.carbon
+++ b/toolchain/check/testdata/return/fail_call_in_type.carbon
@@ -11,9 +11,10 @@
 // TODO: Some variant of this should work, once compile-time function calls are
 // supported.
 fn ReturnType() -> type { return i32; }
-// CHECK:STDERR: fail_call_in_type.carbon:[[@LINE+3]]:13: error: cannot evaluate type expression [TypeExprEvaluationFailure]
+// CHECK:STDERR: fail_call_in_type.carbon:[[@LINE+4]]:13: error: cannot evaluate type expression [TypeExprEvaluationFailure]
 // CHECK:STDERR: fn Six() -> ReturnType() { return 6; }
 // CHECK:STDERR:             ^~~~~~~~~~~~
+// CHECK:STDERR:
 fn Six() -> ReturnType() { return 6; }
 
 // CHECK:STDOUT: --- fail_call_in_type.carbon
@@ -56,8 +57,8 @@ fn Six() -> ReturnType() { return 6; }
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %ReturnType.ref: %ReturnType.type = name_ref ReturnType, file.%ReturnType.decl [template = constants.%ReturnType]
 // CHECK:STDOUT:     %ReturnType.call: init type = call %ReturnType.ref()
-// CHECK:STDOUT:     %.loc17_24.1: type = value_of_initializer %ReturnType.call
-// CHECK:STDOUT:     %.loc17_24.2: type = converted %ReturnType.call, %.loc17_24.1
+// CHECK:STDOUT:     %.loc18_24.1: type = value_of_initializer %ReturnType.call
+// CHECK:STDOUT:     %.loc18_24.2: type = converted %ReturnType.call, %.loc18_24.1
 // CHECK:STDOUT:     %return.param: ref <error> = out_param runtime_param0
 // CHECK:STDOUT:     %return: ref <error> = return_slot %return.param
 // CHECK:STDOUT:   }
diff --git a/toolchain/check/testdata/return/fail_error_in_type.carbon b/toolchain/check/testdata/return/fail_error_in_type.carbon
index 9e66a4eb950d..ebcf90a38f21 100644
--- a/toolchain/check/testdata/return/fail_error_in_type.carbon
+++ b/toolchain/check/testdata/return/fail_error_in_type.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/return/fail_error_in_type.carbon
 
-// CHECK:STDERR: fail_error_in_type.carbon:[[@LINE+3]]:13: error: name `x` not found [NameNotFound]
+// CHECK:STDERR: fail_error_in_type.carbon:[[@LINE+4]]:13: error: name `x` not found [NameNotFound]
 // CHECK:STDERR: fn Six() -> x;
 // CHECK:STDERR:             ^
+// CHECK:STDERR:
 fn Six() -> x;
 
 // CHECK:STDOUT: --- fail_error_in_type.carbon
diff --git a/toolchain/check/testdata/return/fail_let_in_type.carbon b/toolchain/check/testdata/return/fail_let_in_type.carbon
index 1a40e50f9e77..29c65b61ef5a 100644
--- a/toolchain/check/testdata/return/fail_let_in_type.carbon
+++ b/toolchain/check/testdata/return/fail_let_in_type.carbon
@@ -28,13 +28,14 @@ let y:! type = i32;
 fn HalfDozen() -> y { return 6; }
 
 // TODO: This should work.
-// CHECK:STDERR: fail_let_in_type.carbon:[[@LINE+7]]:14: error: semantics TODO: ``let` compile time binding outside function or interface` [SemanticsTodo]
+// CHECK:STDERR: fail_let_in_type.carbon:[[@LINE+8]]:14: error: semantics TODO: ``let` compile time binding outside function or interface` [SemanticsTodo]
 // CHECK:STDERR: let template z:! type = i32;
 // CHECK:STDERR:              ^~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_let_in_type.carbon:[[@LINE+3]]:5: error: semantics TODO: `HandleTemplate` [SemanticsTodo]
+// CHECK:STDERR: fail_let_in_type.carbon:[[@LINE+4]]:5: error: semantics TODO: `HandleTemplate` [SemanticsTodo]
 // CHECK:STDERR: let template z:! type = i32;
 // CHECK:STDERR:     ^~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 let template z:! type = i32;
 fn FirstPerfectNumber() -> z { return 6; }
 
diff --git a/toolchain/check/testdata/return/fail_missing_return.carbon b/toolchain/check/testdata/return/fail_missing_return.carbon
index e0c3f0d4738f..86efed946192 100644
--- a/toolchain/check/testdata/return/fail_missing_return.carbon
+++ b/toolchain/check/testdata/return/fail_missing_return.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/return/fail_missing_return.carbon
 
 fn Main() -> i32 {
-// CHECK:STDERR: fail_missing_return.carbon:[[@LINE+3]]:1: error: missing `return` at end of function with declared return type [MissingReturnStatement]
+// CHECK:STDERR: fail_missing_return.carbon:[[@LINE+4]]:1: error: missing `return` at end of function with declared return type [MissingReturnStatement]
 // CHECK:STDERR: }
 // CHECK:STDERR: ^
+// CHECK:STDERR:
 }
 
 // CHECK:STDOUT: --- fail_missing_return.carbon
diff --git a/toolchain/check/testdata/return/fail_missing_return_empty_tuple.carbon b/toolchain/check/testdata/return/fail_missing_return_empty_tuple.carbon
index 2bd80879d317..7f46e46a71f6 100644
--- a/toolchain/check/testdata/return/fail_missing_return_empty_tuple.carbon
+++ b/toolchain/check/testdata/return/fail_missing_return_empty_tuple.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/return/fail_missing_return_empty_tuple.carbon
 
 fn F() -> () {
-// CHECK:STDERR: fail_missing_return_empty_tuple.carbon:[[@LINE+3]]:1: error: missing `return` at end of function with declared return type [MissingReturnStatement]
+// CHECK:STDERR: fail_missing_return_empty_tuple.carbon:[[@LINE+4]]:1: error: missing `return` at end of function with declared return type [MissingReturnStatement]
 // CHECK:STDERR: }
 // CHECK:STDERR: ^
+// CHECK:STDERR:
 }
 
 // CHECK:STDOUT: --- fail_missing_return_empty_tuple.carbon
diff --git a/toolchain/check/testdata/return/fail_return_var_no_returned_var.carbon b/toolchain/check/testdata/return/fail_return_var_no_returned_var.carbon
index 4fce34992101..92ef87a28b32 100644
--- a/toolchain/check/testdata/return/fail_return_var_no_returned_var.carbon
+++ b/toolchain/check/testdata/return/fail_return_var_no_returned_var.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/return/fail_return_var_no_returned_var.carbon
 
 fn Procedure() -> i32 {
-  // CHECK:STDERR: fail_return_var_no_returned_var.carbon:[[@LINE+3]]:3: error: `return var;` with no `returned var` in scope [ReturnVarWithNoReturnedVar]
+  // CHECK:STDERR: fail_return_var_no_returned_var.carbon:[[@LINE+4]]:3: error: `return var;` with no `returned var` in scope [ReturnVarWithNoReturnedVar]
   // CHECK:STDERR:   return var;
   // CHECK:STDERR:   ^~~~~~~~~~~
+  // CHECK:STDERR:
   return var;
 }
 
diff --git a/toolchain/check/testdata/return/fail_return_with_returned_var.carbon b/toolchain/check/testdata/return/fail_return_with_returned_var.carbon
index db7ce6a500f3..408147c55ef4 100644
--- a/toolchain/check/testdata/return/fail_return_with_returned_var.carbon
+++ b/toolchain/check/testdata/return/fail_return_with_returned_var.carbon
@@ -23,12 +23,13 @@ fn F() -> i32 {
 class C { var a: i32; var b: i32; }
 fn G() -> C {
   returned var c: C = {.a = 1, .b = 2};
-  // CHECK:STDERR: fail_return_with_returned_var.carbon:[[@LINE+6]]:3: error: can only `return var;` in the scope of a `returned var` [ReturnExprWithReturnedVar]
+  // CHECK:STDERR: fail_return_with_returned_var.carbon:[[@LINE+7]]:3: error: can only `return var;` in the scope of a `returned var` [ReturnExprWithReturnedVar]
   // CHECK:STDERR:   return c;
   // CHECK:STDERR:   ^~~~~~~~~
   // CHECK:STDERR: fail_return_with_returned_var.carbon:[[@LINE-4]]:16: note: `returned var` was declared here [ReturnedVarHere]
   // CHECK:STDERR:   returned var c: C = {.a = 1, .b = 2};
   // CHECK:STDERR:                ^
+  // CHECK:STDERR:
   return c;
 }
 
diff --git a/toolchain/check/testdata/return/fail_returned_var_no_return_type.carbon b/toolchain/check/testdata/return/fail_returned_var_no_return_type.carbon
index 08478b66afd4..f6895e57a92a 100644
--- a/toolchain/check/testdata/return/fail_returned_var_no_return_type.carbon
+++ b/toolchain/check/testdata/return/fail_returned_var_no_return_type.carbon
@@ -29,12 +29,13 @@ fn Procedure() {
 library "[[@TEST_NAME]]";
 
 fn ForgotReturnType() {
-  // CHECK:STDERR: fail_forgot_return_type.carbon:[[@LINE+6]]:3: error: cannot declare a `returned var` in this function [ReturnedVarWithNoReturnType]
+  // CHECK:STDERR: fail_forgot_return_type.carbon:[[@LINE+7]]:3: error: cannot declare a `returned var` in this function [ReturnedVarWithNoReturnType]
   // CHECK:STDERR:   returned var v: () = ();
   // CHECK:STDERR:   ^~~~~~~~
   // CHECK:STDERR: fail_forgot_return_type.carbon:[[@LINE-4]]:1: note: there was no return type provided [ReturnTypeOmittedNote]
   // CHECK:STDERR: fn ForgotReturnType() {
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   returned var v: () = ();
   return var;
 }
@@ -99,10 +100,10 @@ fn ForgotReturnType() {
 // CHECK:STDOUT: fn @ForgotReturnType() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %v: %empty_tuple.type = bind_name v, <error>
-// CHECK:STDOUT:   %.loc11_25: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:   %.loc12_25: %empty_tuple.type = tuple_literal ()
 // CHECK:STDOUT:   assign <error>, <error>
 // CHECK:STDOUT:   %tuple: %empty_tuple.type = tuple_value () [template = constants.%empty_tuple]
-// CHECK:STDOUT:   %.loc11_16: %empty_tuple.type = converted %v, %tuple [template = constants.%empty_tuple]
-// CHECK:STDOUT:   return %.loc11_16
+// CHECK:STDOUT:   %.loc12_16: %empty_tuple.type = converted %v, %tuple [template = constants.%empty_tuple]
+// CHECK:STDOUT:   return %.loc12_16
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/return/fail_returned_var_shadow.carbon b/toolchain/check/testdata/return/fail_returned_var_shadow.carbon
index 39662c03dc78..8fad920ffb07 100644
--- a/toolchain/check/testdata/return/fail_returned_var_shadow.carbon
+++ b/toolchain/check/testdata/return/fail_returned_var_shadow.carbon
@@ -27,12 +27,13 @@ fn DifferentScopes() -> i32 {
   if (true) {
     returned var v: i32 = 0;
     if (true) {
-      // CHECK:STDERR: fail_returned_var_shadow.carbon:[[@LINE+6]]:20: error: cannot declare a `returned var` in the scope of another `returned var` [ReturnedVarShadowed]
+      // CHECK:STDERR: fail_returned_var_shadow.carbon:[[@LINE+7]]:20: error: cannot declare a `returned var` in the scope of another `returned var` [ReturnedVarShadowed]
       // CHECK:STDERR:       returned var w: i32 = 1;
       // CHECK:STDERR:                    ^
       // CHECK:STDERR: fail_returned_var_shadow.carbon:[[@LINE-5]]:18: note: `returned var` was declared here [ReturnedVarHere]
       // CHECK:STDERR:     returned var v: i32 = 0;
       // CHECK:STDERR:                  ^
+      // CHECK:STDERR:
       returned var w: i32 = 1;
     }
   }
@@ -158,25 +159,25 @@ fn DifferentScopes() -> i32 {
 // CHECK:STDOUT:   %w.var: ref %i32 = var w
 // CHECK:STDOUT:   %w: ref %i32 = bind_name w, %w.var
 // CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [template = constants.%int_1.5b8]
-// CHECK:STDOUT:   %impl.elem0.loc36: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
-// CHECK:STDOUT:   %Convert.bound.loc36: <bound method> = bound_method %int_1, %impl.elem0.loc36 [template = constants.%Convert.bound.ab5]
-// CHECK:STDOUT:   %Convert.specific_fn.loc36: <specific function> = specific_function %Convert.bound.loc36, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.70c]
-// CHECK:STDOUT:   %int.convert_checked.loc36: init %i32 = call %Convert.specific_fn.loc36(%int_1) [template = constants.%int_1.5d2]
-// CHECK:STDOUT:   %.loc36: init %i32 = converted %int_1, %int.convert_checked.loc36 [template = constants.%int_1.5d2]
-// CHECK:STDOUT:   assign %w.var, %.loc36
+// CHECK:STDOUT:   %impl.elem0.loc37: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
+// CHECK:STDOUT:   %Convert.bound.loc37: <bound method> = bound_method %int_1, %impl.elem0.loc37 [template = constants.%Convert.bound.ab5]
+// CHECK:STDOUT:   %Convert.specific_fn.loc37: <specific function> = specific_function %Convert.bound.loc37, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.70c]
+// CHECK:STDOUT:   %int.convert_checked.loc37: init %i32 = call %Convert.specific_fn.loc37(%int_1) [template = constants.%int_1.5d2]
+// CHECK:STDOUT:   %.loc37: init %i32 = converted %int_1, %int.convert_checked.loc37 [template = constants.%int_1.5d2]
+// CHECK:STDOUT:   assign %w.var, %.loc37
 // CHECK:STDOUT:   br !if.else.loc29
 // CHECK:STDOUT:
 // CHECK:STDOUT: !if.else.loc29:
 // CHECK:STDOUT:   br !if.else.loc27
 // CHECK:STDOUT:
 // CHECK:STDOUT: !if.else.loc27:
-// CHECK:STDOUT:   %int_0.loc39: Core.IntLiteral = int_value 0 [template = constants.%int_0.5c6]
-// CHECK:STDOUT:   %impl.elem0.loc39: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
-// CHECK:STDOUT:   %Convert.bound.loc39: <bound method> = bound_method %int_0.loc39, %impl.elem0.loc39 [template = constants.%Convert.bound.d04]
-// CHECK:STDOUT:   %Convert.specific_fn.loc39: <specific function> = specific_function %Convert.bound.loc39, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.d62]
-// CHECK:STDOUT:   %int.convert_checked.loc39: init %i32 = call %Convert.specific_fn.loc39(%int_0.loc39) [template = constants.%int_0.6a9]
-// CHECK:STDOUT:   %.loc39_11.1: %i32 = value_of_initializer %int.convert_checked.loc39 [template = constants.%int_0.6a9]
-// CHECK:STDOUT:   %.loc39_11.2: %i32 = converted %int_0.loc39, %.loc39_11.1 [template = constants.%int_0.6a9]
-// CHECK:STDOUT:   return %.loc39_11.2
+// CHECK:STDOUT:   %int_0.loc40: Core.IntLiteral = int_value 0 [template = constants.%int_0.5c6]
+// CHECK:STDOUT:   %impl.elem0.loc40: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
+// CHECK:STDOUT:   %Convert.bound.loc40: <bound method> = bound_method %int_0.loc40, %impl.elem0.loc40 [template = constants.%Convert.bound.d04]
+// CHECK:STDOUT:   %Convert.specific_fn.loc40: <specific function> = specific_function %Convert.bound.loc40, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn.d62]
+// CHECK:STDOUT:   %int.convert_checked.loc40: init %i32 = call %Convert.specific_fn.loc40(%int_0.loc40) [template = constants.%int_0.6a9]
+// CHECK:STDOUT:   %.loc40_11.1: %i32 = value_of_initializer %int.convert_checked.loc40 [template = constants.%int_0.6a9]
+// CHECK:STDOUT:   %.loc40_11.2: %i32 = converted %int_0.loc40, %.loc40_11.1 [template = constants.%int_0.6a9]
+// CHECK:STDOUT:   return %.loc40_11.2
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/return/fail_returned_var_type.carbon b/toolchain/check/testdata/return/fail_returned_var_type.carbon
index 112c2f5d91ad..4a3009e4d049 100644
--- a/toolchain/check/testdata/return/fail_returned_var_type.carbon
+++ b/toolchain/check/testdata/return/fail_returned_var_type.carbon
@@ -9,12 +9,13 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/return/fail_returned_var_type.carbon
 
 fn Mismatch() -> i32 {
-  // CHECK:STDERR: fail_returned_var_type.carbon:[[@LINE+6]]:19: error: type `f64` of `returned var` does not match return type of enclosing function [ReturnedVarWrongType]
+  // CHECK:STDERR: fail_returned_var_type.carbon:[[@LINE+7]]:19: error: type `f64` of `returned var` does not match return type of enclosing function [ReturnedVarWrongType]
   // CHECK:STDERR:   returned var v: f64 = 0.0;
   // CHECK:STDERR:                   ^~~
   // CHECK:STDERR: fail_returned_var_type.carbon:[[@LINE-4]]:15: note: return type of function is `i32` [ReturnTypeHereNote]
   // CHECK:STDERR: fn Mismatch() -> i32 {
   // CHECK:STDERR:               ^~~~~~
+  // CHECK:STDERR:
   returned var v: f64 = 0.0;
   return var;
 }
diff --git a/toolchain/check/testdata/return/fail_type_mismatch.carbon b/toolchain/check/testdata/return/fail_type_mismatch.carbon
index f72638dde0cc..161c7bc6ab92 100644
--- a/toolchain/check/testdata/return/fail_type_mismatch.carbon
+++ b/toolchain/check/testdata/return/fail_type_mismatch.carbon
@@ -9,12 +9,13 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/return/fail_type_mismatch.carbon
 
 fn Main() -> i32 {
-  // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+6]]:3: error: cannot implicitly convert from `f64` to `i32` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+7]]:3: error: cannot implicitly convert from `f64` to `i32` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   return 1.0;
   // CHECK:STDERR:   ^~~~~~~~~~~
-  // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+3]]:3: note: type `f64` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR: fail_type_mismatch.carbon:[[@LINE+4]]:3: note: type `f64` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]
   // CHECK:STDERR:   return 1.0;
   // CHECK:STDERR:   ^~~~~~~~~~~
+  // CHECK:STDERR:
   return 1.0;
 }
 
@@ -57,7 +58,7 @@ fn Main() -> i32 {
 // CHECK:STDOUT: fn @Main() -> %i32 {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %float: f64 = float_literal 1 [template = constants.%float]
-// CHECK:STDOUT:   %.loc18: %i32 = converted %float, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc19: %i32 = converted %float, <error> [template = <error>]
 // CHECK:STDOUT:   return <error>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/return/fail_value_disallowed.carbon b/toolchain/check/testdata/return/fail_value_disallowed.carbon
index 08682bc655f9..b1ea9dd1b445 100644
--- a/toolchain/check/testdata/return/fail_value_disallowed.carbon
+++ b/toolchain/check/testdata/return/fail_value_disallowed.carbon
@@ -9,12 +9,13 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/return/fail_value_disallowed.carbon
 
 fn Main() {
-  // CHECK:STDERR: fail_value_disallowed.carbon:[[@LINE+6]]:3: error: no return expression should be provided in this context [ReturnStatementDisallowExpr]
+  // CHECK:STDERR: fail_value_disallowed.carbon:[[@LINE+7]]:3: error: no return expression should be provided in this context [ReturnStatementDisallowExpr]
   // CHECK:STDERR:   return 0;
   // CHECK:STDERR:   ^~~~~~~~~
   // CHECK:STDERR: fail_value_disallowed.carbon:[[@LINE-4]]:1: note: there was no return type provided [ReturnTypeOmittedNote]
   // CHECK:STDERR: fn Main() {
   // CHECK:STDERR: ^~~~~~~~~~~
+  // CHECK:STDERR:
   return 0;
 }
 
diff --git a/toolchain/check/testdata/return/fail_value_missing.carbon b/toolchain/check/testdata/return/fail_value_missing.carbon
index 01b963d087a3..0622aa8eeb12 100644
--- a/toolchain/check/testdata/return/fail_value_missing.carbon
+++ b/toolchain/check/testdata/return/fail_value_missing.carbon
@@ -9,12 +9,13 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/return/fail_value_missing.carbon
 
 fn Main() -> i32 {
-  // CHECK:STDERR: fail_value_missing.carbon:[[@LINE+6]]:3: error: missing return value [ReturnStatementMissingExpr]
+  // CHECK:STDERR: fail_value_missing.carbon:[[@LINE+7]]:3: error: missing return value [ReturnStatementMissingExpr]
   // CHECK:STDERR:   return;
   // CHECK:STDERR:   ^~~~~~~
   // CHECK:STDERR: fail_value_missing.carbon:[[@LINE-4]]:11: note: return type of function is `i32` [ReturnTypeHereNote]
   // CHECK:STDERR: fn Main() -> i32 {
   // CHECK:STDERR:           ^~~~~~
+  // CHECK:STDERR:
   return;
 }
 
diff --git a/toolchain/check/testdata/return/fail_var_in_type.carbon b/toolchain/check/testdata/return/fail_var_in_type.carbon
index 7a547a33e792..5a60461f324a 100644
--- a/toolchain/check/testdata/return/fail_var_in_type.carbon
+++ b/toolchain/check/testdata/return/fail_var_in_type.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/return/fail_var_in_type.carbon
 
 var x: type = i32;
-// CHECK:STDERR: fail_var_in_type.carbon:[[@LINE+3]]:13: error: cannot evaluate type expression [TypeExprEvaluationFailure]
+// CHECK:STDERR: fail_var_in_type.carbon:[[@LINE+4]]:13: error: cannot evaluate type expression [TypeExprEvaluationFailure]
 // CHECK:STDERR: fn Six() -> x { return 6; }
 // CHECK:STDERR:             ^
+// CHECK:STDERR:
 fn Six() -> x { return 6; }
 
 // CHECK:STDOUT: --- fail_var_in_type.carbon
@@ -46,7 +47,7 @@ fn Six() -> x { return 6; }
 // CHECK:STDOUT:     %return.param_patt: <error> = out_param_pattern %return.patt, runtime_param0
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     %x.ref: ref type = name_ref x, file.%x
-// CHECK:STDOUT:     %.loc15: type = bind_value %x.ref
+// CHECK:STDOUT:     %.loc16: type = bind_value %x.ref
 // CHECK:STDOUT:     %return.param: ref <error> = out_param runtime_param0
 // CHECK:STDOUT:     %return: ref <error> = return_slot %return.param
 // CHECK:STDOUT:   }
diff --git a/toolchain/check/testdata/struct/fail_access_into_invalid.carbon b/toolchain/check/testdata/struct/fail_access_into_invalid.carbon
index 47327304a954..5c55d73466b0 100644
--- a/toolchain/check/testdata/struct/fail_access_into_invalid.carbon
+++ b/toolchain/check/testdata/struct/fail_access_into_invalid.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/struct/fail_access_into_invalid.carbon
 
 
-// CHECK:STDERR: fail_access_into_invalid.carbon:[[@LINE+3]]:10: error: name `a` not found [NameNotFound]
+// CHECK:STDERR: fail_access_into_invalid.carbon:[[@LINE+4]]:10: error: name `a` not found [NameNotFound]
 // CHECK:STDERR: fn F() { a.b; }
 // CHECK:STDERR:          ^
+// CHECK:STDERR:
 fn F() { a.b; }
 
 // CHECK:STDOUT: --- fail_access_into_invalid.carbon
diff --git a/toolchain/check/testdata/struct/fail_assign_empty.carbon b/toolchain/check/testdata/struct/fail_assign_empty.carbon
index ec1b9e887e1e..4a83370f8cb9 100644
--- a/toolchain/check/testdata/struct/fail_assign_empty.carbon
+++ b/toolchain/check/testdata/struct/fail_assign_empty.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/struct/fail_assign_empty.carbon
 
-// CHECK:STDERR: fail_assign_empty.carbon:[[@LINE+3]]:20: error: cannot initialize struct with 1 field from struct with 0 fields [StructInitElementCountMismatch]
+// CHECK:STDERR: fail_assign_empty.carbon:[[@LINE+4]]:20: error: cannot initialize struct with 1 field from struct with 0 fields [StructInitElementCountMismatch]
 // CHECK:STDERR: var x: {.a: i32} = {};
 // CHECK:STDERR:                    ^~
+// CHECK:STDERR:
 var x: {.a: i32} = {};
 
 // CHECK:STDOUT: --- fail_assign_empty.carbon
@@ -42,7 +43,7 @@ var x: {.a: i32} = {};
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %.loc14: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %.loc15: %empty_struct_type = struct_literal ()
 // CHECK:STDOUT:   assign file.%x.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/struct/fail_assign_to_empty.carbon b/toolchain/check/testdata/struct/fail_assign_to_empty.carbon
index 29fe517c24e1..4b491cf4d529 100644
--- a/toolchain/check/testdata/struct/fail_assign_to_empty.carbon
+++ b/toolchain/check/testdata/struct/fail_assign_to_empty.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/struct/fail_assign_to_empty.carbon
 
-// CHECK:STDERR: fail_assign_to_empty.carbon:[[@LINE+3]]:13: error: cannot initialize struct with 0 fields from struct with 1 field [StructInitElementCountMismatch]
+// CHECK:STDERR: fail_assign_to_empty.carbon:[[@LINE+4]]:13: error: cannot initialize struct with 0 fields from struct with 1 field [StructInitElementCountMismatch]
 // CHECK:STDERR: var x: {} = {.a = 1};
 // CHECK:STDERR:             ^~~~~~~~
+// CHECK:STDERR:
 var x: {} = {.a = 1};
 
 // CHECK:STDOUT: --- fail_assign_to_empty.carbon
@@ -41,7 +42,7 @@ var x: {} = {.a = 1};
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [template = constants.%int_1]
-// CHECK:STDOUT:   %.loc14: %struct_type.a = struct_literal (%int_1)
+// CHECK:STDOUT:   %.loc15: %struct_type.a = struct_literal (%int_1)
 // CHECK:STDOUT:   assign file.%x.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/struct/fail_duplicate_name.carbon b/toolchain/check/testdata/struct/fail_duplicate_name.carbon
index 3393053f07ca..c787d3c079ec 100644
--- a/toolchain/check/testdata/struct/fail_duplicate_name.carbon
+++ b/toolchain/check/testdata/struct/fail_duplicate_name.carbon
@@ -44,12 +44,13 @@ let w: i32 = {.def = 1, .def = 2}.def;
 // CHECK:STDERR:
 var x: {.a: i32} = {.a = 1, .a = 2};
 
-// CHECK:STDERR: fail_duplicate_name.carbon:[[@LINE+6]]:39: error: duplicated field name `b` in struct literal [StructNameDuplicate]
+// CHECK:STDERR: fail_duplicate_name.carbon:[[@LINE+7]]:39: error: duplicated field name `b` in struct literal [StructNameDuplicate]
 // CHECK:STDERR: var y: {.b: i32, .c: i32} = {.b = 3, .b = 4};
 // CHECK:STDERR:                                       ^
-// CHECK:STDERR: fail_duplicate_name.carbon:[[@LINE+3]]:31: note: field with the same name here [StructNamePrevious]
+// CHECK:STDERR: fail_duplicate_name.carbon:[[@LINE+4]]:31: note: field with the same name here [StructNamePrevious]
 // CHECK:STDERR: var y: {.b: i32, .c: i32} = {.b = 3, .b = 4};
 // CHECK:STDERR:                               ^
+// CHECK:STDERR:
 var y: {.b: i32, .c: i32} = {.b = 3, .b = 4};
 
 // CHECK:STDOUT: --- fail_duplicate_name.carbon
diff --git a/toolchain/check/testdata/struct/fail_field_name_mismatch.carbon b/toolchain/check/testdata/struct/fail_field_name_mismatch.carbon
index bca33b93b9ef..347280bc28e2 100644
--- a/toolchain/check/testdata/struct/fail_field_name_mismatch.carbon
+++ b/toolchain/check/testdata/struct/fail_field_name_mismatch.carbon
@@ -14,9 +14,10 @@
 // CHECK:STDERR:
 var x: {.a: i32} = {.b = 1};
 
-// CHECK:STDERR: fail_field_name_mismatch.carbon:[[@LINE+3]]:20: error: cannot convert from struct type `{.a: i32}` to `{.b: i32}`: missing field `b` in source type [StructInitMissingFieldInConversion]
+// CHECK:STDERR: fail_field_name_mismatch.carbon:[[@LINE+4]]:20: error: cannot convert from struct type `{.a: i32}` to `{.b: i32}`: missing field `b` in source type [StructInitMissingFieldInConversion]
 // CHECK:STDERR: var y: {.b: i32} = x;
 // CHECK:STDERR:                    ^
+// CHECK:STDERR:
 var y: {.b: i32} = x;
 
 // CHECK:STDOUT: --- fail_field_name_mismatch.carbon
diff --git a/toolchain/check/testdata/struct/fail_field_type_mismatch.carbon b/toolchain/check/testdata/struct/fail_field_type_mismatch.carbon
index e076a323a04f..e2996840d84e 100644
--- a/toolchain/check/testdata/struct/fail_field_type_mismatch.carbon
+++ b/toolchain/check/testdata/struct/fail_field_type_mismatch.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/struct/fail_field_type_mismatch.carbon
 
-// CHECK:STDERR: fail_field_type_mismatch.carbon:[[@LINE+3]]:20: error: missing value for field `a` in struct initialization [StructInitMissingFieldInLiteral]
+// CHECK:STDERR: fail_field_type_mismatch.carbon:[[@LINE+4]]:20: error: missing value for field `a` in struct initialization [StructInitMissingFieldInLiteral]
 // CHECK:STDERR: var x: {.a: i32} = {.b = 1.0};
 // CHECK:STDERR:                    ^~~~~~~~~~
+// CHECK:STDERR:
 var x: {.a: i32} = {.b = 1.0};
 
 // CHECK:STDOUT: --- fail_field_type_mismatch.carbon
@@ -44,7 +45,7 @@ var x: {.a: i32} = {.b = 1.0};
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %float: f64 = float_literal 1 [template = constants.%float]
-// CHECK:STDOUT:   %.loc14: %struct_type.b = struct_literal (%float)
+// CHECK:STDOUT:   %.loc15: %struct_type.b = struct_literal (%float)
 // CHECK:STDOUT:   assign file.%x.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/struct/fail_keyword_name.carbon b/toolchain/check/testdata/struct/fail_keyword_name.carbon
index 6958dfc372db..c2f155a60e97 100644
--- a/toolchain/check/testdata/struct/fail_keyword_name.carbon
+++ b/toolchain/check/testdata/struct/fail_keyword_name.carbon
@@ -18,9 +18,10 @@
 // CHECK:STDERR:
 fn F() -> {.class: i32};
 
-// CHECK:STDERR: fail_keyword_name.carbon:[[@LINE+3]]:19: error: expected identifier after `.` [ExpectedIdentifierAfterPeriodOrArrow]
+// CHECK:STDERR: fail_keyword_name.carbon:[[@LINE+4]]:19: error: expected identifier after `.` [ExpectedIdentifierAfterPeriodOrArrow]
 // CHECK:STDERR: fn G() { return {.return = 5}; };
 // CHECK:STDERR:                   ^~~~~~
+// CHECK:STDERR:
 fn G() { return {.return = 5}; };
 
 // CHECK:STDOUT: --- fail_keyword_name.carbon
diff --git a/toolchain/check/testdata/struct/fail_member_access_type.carbon b/toolchain/check/testdata/struct/fail_member_access_type.carbon
index d6f70cf2281c..eb898d4fda92 100644
--- a/toolchain/check/testdata/struct/fail_member_access_type.carbon
+++ b/toolchain/check/testdata/struct/fail_member_access_type.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/struct/fail_member_access_type.carbon
 
 var x: {.a: f64} = {.a = 4.0};
-// CHECK:STDERR: fail_member_access_type.carbon:[[@LINE+3]]:14: error: type `{.a: f64}` does not have a member `b` [QualifiedExprNameNotFound]
+// CHECK:STDERR: fail_member_access_type.carbon:[[@LINE+4]]:14: error: type `{.a: f64}` does not have a member `b` [QualifiedExprNameNotFound]
 // CHECK:STDERR: var y: i32 = x.b;
 // CHECK:STDERR:              ^~~
+// CHECK:STDERR:
 var y: i32 = x.b;
 
 // CHECK:STDOUT: --- fail_member_access_type.carbon
diff --git a/toolchain/check/testdata/struct/fail_member_of_function.carbon b/toolchain/check/testdata/struct/fail_member_of_function.carbon
index c8198ca2a0af..e0bab470caec 100644
--- a/toolchain/check/testdata/struct/fail_member_of_function.carbon
+++ b/toolchain/check/testdata/struct/fail_member_of_function.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/struct/fail_member_of_function.carbon
 
 fn A() {
-  // CHECK:STDERR: fail_member_of_function.carbon:[[@LINE+3]]:3: error: expression cannot be used as a value [UseOfNonExprAsValue]
+  // CHECK:STDERR: fail_member_of_function.carbon:[[@LINE+4]]:3: error: expression cannot be used as a value [UseOfNonExprAsValue]
   // CHECK:STDERR:   A.y;
   // CHECK:STDERR:   ^
+  // CHECK:STDERR:
   A.y;
 }
 
diff --git a/toolchain/check/testdata/struct/fail_non_member_access.carbon b/toolchain/check/testdata/struct/fail_non_member_access.carbon
index 98803488b2a2..7039e62834f6 100644
--- a/toolchain/check/testdata/struct/fail_non_member_access.carbon
+++ b/toolchain/check/testdata/struct/fail_non_member_access.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/struct/fail_non_member_access.carbon
 
 var x: {.a: i32} = {.a = 4};
-// CHECK:STDERR: fail_non_member_access.carbon:[[@LINE+3]]:14: error: type `{.a: i32}` does not have a member `b` [QualifiedExprNameNotFound]
+// CHECK:STDERR: fail_non_member_access.carbon:[[@LINE+4]]:14: error: type `{.a: i32}` does not have a member `b` [QualifiedExprNameNotFound]
 // CHECK:STDERR: var y: i32 = x.b;
 // CHECK:STDERR:              ^~~
+// CHECK:STDERR:
 var y: i32 = x.b;
 
 // CHECK:STDOUT: --- fail_non_member_access.carbon
diff --git a/toolchain/check/testdata/struct/fail_too_few_values.carbon b/toolchain/check/testdata/struct/fail_too_few_values.carbon
index ed8f41d156c6..8f59050a7b6c 100644
--- a/toolchain/check/testdata/struct/fail_too_few_values.carbon
+++ b/toolchain/check/testdata/struct/fail_too_few_values.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/struct/fail_too_few_values.carbon
 
-// CHECK:STDERR: fail_too_few_values.carbon:[[@LINE+3]]:29: error: cannot initialize struct with 2 fields from struct with 1 field [StructInitElementCountMismatch]
+// CHECK:STDERR: fail_too_few_values.carbon:[[@LINE+4]]:29: error: cannot initialize struct with 2 fields from struct with 1 field [StructInitElementCountMismatch]
 // CHECK:STDERR: var x: {.a: i32, .b: i32} = {.a = 1};
 // CHECK:STDERR:                             ^~~~~~~~
+// CHECK:STDERR:
 var x: {.a: i32, .b: i32} = {.a = 1};
 
 // CHECK:STDOUT: --- fail_too_few_values.carbon
@@ -44,7 +45,7 @@ var x: {.a: i32, .b: i32} = {.a = 1};
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [template = constants.%int_1]
-// CHECK:STDOUT:   %.loc14: %struct_type.a = struct_literal (%int_1)
+// CHECK:STDOUT:   %.loc15: %struct_type.a = struct_literal (%int_1)
 // CHECK:STDOUT:   assign file.%x.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/struct/fail_type_assign.carbon b/toolchain/check/testdata/struct/fail_type_assign.carbon
index 8e24511caaac..16e36bd80d12 100644
--- a/toolchain/check/testdata/struct/fail_type_assign.carbon
+++ b/toolchain/check/testdata/struct/fail_type_assign.carbon
@@ -8,12 +8,13 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/struct/fail_type_assign.carbon
 
-// CHECK:STDERR: fail_type_assign.carbon:[[@LINE+6]]:1: error: cannot implicitly convert from `type` to `{.a: i32}` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_type_assign.carbon:[[@LINE+7]]:1: error: cannot implicitly convert from `type` to `{.a: i32}` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var x: {.a: i32} = {.a: i32};
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_type_assign.carbon:[[@LINE+3]]:1: note: type `type` does not implement interface `Core.ImplicitAs({.a: i32})` [MissingImplInMemberAccessNote]
+// CHECK:STDERR: fail_type_assign.carbon:[[@LINE+4]]:1: note: type `type` does not implement interface `Core.ImplicitAs({.a: i32})` [MissingImplInMemberAccessNote]
 // CHECK:STDERR: var x: {.a: i32} = {.a: i32};
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 var x: {.a: i32} = {.a: i32};
 
 // CHECK:STDOUT: --- fail_type_assign.carbon
@@ -48,7 +49,7 @@ var x: {.a: i32} = {.a: i32};
 // CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [template = constants.%int_32]
 // CHECK:STDOUT:   %i32: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
 // CHECK:STDOUT:   %struct_type.a: type = struct_type {.a: %i32} [template = constants.%struct_type.a]
-// CHECK:STDOUT:   %.loc17: %struct_type.a = converted %struct_type.a, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc18: %struct_type.a = converted %struct_type.a, <error> [template = <error>]
 // CHECK:STDOUT:   assign file.%x.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/struct/fail_value_as_type.carbon b/toolchain/check/testdata/struct/fail_value_as_type.carbon
index 9b0f2925ae5c..9ba9401227b4 100644
--- a/toolchain/check/testdata/struct/fail_value_as_type.carbon
+++ b/toolchain/check/testdata/struct/fail_value_as_type.carbon
@@ -8,12 +8,13 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/struct/fail_value_as_type.carbon
 
-// CHECK:STDERR: fail_value_as_type.carbon:[[@LINE+6]]:8: error: cannot implicitly convert from `{.a: Core.IntLiteral}` to `type` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_value_as_type.carbon:[[@LINE+7]]:8: error: cannot implicitly convert from `{.a: Core.IntLiteral}` to `type` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var x: {.a = 1};
 // CHECK:STDERR:        ^~~~~~~~
-// CHECK:STDERR: fail_value_as_type.carbon:[[@LINE+3]]:8: note: type `{.a: Core.IntLiteral}` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
+// CHECK:STDERR: fail_value_as_type.carbon:[[@LINE+4]]:8: note: type `{.a: Core.IntLiteral}` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
 // CHECK:STDERR: var x: {.a = 1};
 // CHECK:STDERR:        ^~~~~~~~
+// CHECK:STDERR:
 var x: {.a = 1};
 
 // CHECK:STDOUT: --- fail_value_as_type.carbon
diff --git a/toolchain/check/testdata/struct/import.carbon b/toolchain/check/testdata/struct/import.carbon
index ee4518ba5e5b..4b19471a261d 100644
--- a/toolchain/check/testdata/struct/import.carbon
+++ b/toolchain/check/testdata/struct/import.carbon
@@ -43,12 +43,13 @@ var c_bad: C({.c = 1, .d = 2}) = F();
 // --- fail_bad_value.impl.carbon
 
 impl package Implicit;
-// CHECK:STDERR: fail_bad_value.impl.carbon:[[@LINE+6]]:1: error: cannot implicitly convert from `C({.a = 1, .b = 2})` to `C({.a = 3, .b = 4})` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_bad_value.impl.carbon:[[@LINE+7]]:1: error: cannot implicitly convert from `C({.a = 1, .b = 2})` to `C({.a = 3, .b = 4})` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var c_bad: C({.a = 3, .b = 4}) = F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_bad_value.impl.carbon:[[@LINE+3]]:1: note: type `C({.a = 1, .b = 2})` does not implement interface `Core.ImplicitAs(C({.a = 3, .b = 4}))` [MissingImplInMemberAccessNote]
+// CHECK:STDERR: fail_bad_value.impl.carbon:[[@LINE+4]]:1: note: type `C({.a = 1, .b = 2})` does not implement interface `Core.ImplicitAs(C({.a = 3, .b = 4}))` [MissingImplInMemberAccessNote]
 // CHECK:STDERR: var c_bad: C({.a = 3, .b = 4}) = F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 var c_bad: C({.a = 3, .b = 4}) = F();
 
 // CHECK:STDOUT: --- implicit.carbon
@@ -510,9 +511,9 @@ var c_bad: C({.a = 3, .b = 4}) = F();
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %F.ref: %F.type = name_ref F, imports.%import_ref.b37 [template = constants.%F]
-// CHECK:STDOUT:   %.loc9_36: ref %C.a8a = temporary_storage
-// CHECK:STDOUT:   %F.call: init %C.a8a = call %F.ref() to %.loc9_36
-// CHECK:STDOUT:   %.loc9_37: %C.5a7 = converted %F.call, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc10_36: ref %C.a8a = temporary_storage
+// CHECK:STDOUT:   %F.call: init %C.a8a = call %F.ref() to %.loc10_36
+// CHECK:STDOUT:   %.loc10_37: %C.5a7 = converted %F.call, <error> [template = <error>]
 // CHECK:STDOUT:   assign file.%c_bad.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/struct/no_prelude/fail_assign_nested.carbon b/toolchain/check/testdata/struct/no_prelude/fail_assign_nested.carbon
index f024eae8ea6d..efc8b760d131 100644
--- a/toolchain/check/testdata/struct/no_prelude/fail_assign_nested.carbon
+++ b/toolchain/check/testdata/struct/no_prelude/fail_assign_nested.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/struct/no_prelude/fail_assign_nested.carbon
 
-// CHECK:STDERR: fail_assign_nested.carbon:[[@LINE+3]]:19: error: missing value for field `a` in struct initialization [StructInitMissingFieldInLiteral]
+// CHECK:STDERR: fail_assign_nested.carbon:[[@LINE+4]]:19: error: missing value for field `a` in struct initialization [StructInitMissingFieldInLiteral]
 // CHECK:STDERR: var x: {.a: {}} = {.b = {}};
 // CHECK:STDERR:                   ^~~~~~~~~
+// CHECK:STDERR:
 var x: {.a: {}} = {.b = {}};
 
 // CHECK:STDOUT: --- fail_assign_nested.carbon
@@ -31,8 +32,8 @@ var x: {.a: {}} = {.b = {}};
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %.loc14_26: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:   %.loc14_27: %struct_type.b = struct_literal (%.loc14_26)
+// CHECK:STDOUT:   %.loc15_26: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %.loc15_27: %struct_type.b = struct_literal (%.loc15_26)
 // CHECK:STDOUT:   assign file.%x.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/struct/no_prelude/fail_nested_incomplete.carbon b/toolchain/check/testdata/struct/no_prelude/fail_nested_incomplete.carbon
index 8306852ac7b0..8d83956e94f3 100644
--- a/toolchain/check/testdata/struct/no_prelude/fail_nested_incomplete.carbon
+++ b/toolchain/check/testdata/struct/no_prelude/fail_nested_incomplete.carbon
@@ -10,12 +10,13 @@
 
 class Incomplete;
 
-// CHECK:STDERR: fail_nested_incomplete.carbon:[[@LINE+6]]:8: error: variable has incomplete type `{.a: Incomplete}` [IncompleteTypeInVarDecl]
+// CHECK:STDERR: fail_nested_incomplete.carbon:[[@LINE+7]]:8: error: variable has incomplete type `{.a: Incomplete}` [IncompleteTypeInVarDecl]
 // CHECK:STDERR: var s: {.a: Incomplete};
 // CHECK:STDERR:        ^~~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_nested_incomplete.carbon:[[@LINE-5]]:1: note: class was forward declared here [ClassForwardDeclaredHere]
 // CHECK:STDERR: class Incomplete;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 var s: {.a: Incomplete};
 
 var p: Incomplete* = &s.a;
diff --git a/toolchain/check/testdata/tuple/access/fail_access_error.carbon b/toolchain/check/testdata/tuple/access/fail_access_error.carbon
index 67c76733c422..b9304b4323f9 100644
--- a/toolchain/check/testdata/tuple/access/fail_access_error.carbon
+++ b/toolchain/check/testdata/tuple/access/fail_access_error.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/tuple/access/fail_access_error.carbon
 
 var a: (i32, i32) = (12, 6);
-// CHECK:STDERR: fail_access_error.carbon:[[@LINE+3]]:17: error: name `oops` not found [NameNotFound]
+// CHECK:STDERR: fail_access_error.carbon:[[@LINE+4]]:17: error: name `oops` not found [NameNotFound]
 // CHECK:STDERR: var b: i32 = a.(oops);
 // CHECK:STDERR:                 ^~~~
+// CHECK:STDERR:
 var b: i32 = a.(oops);
 
 // CHECK:STDOUT: --- fail_access_error.carbon
diff --git a/toolchain/check/testdata/tuple/access/fail_empty_access.carbon b/toolchain/check/testdata/tuple/access/fail_empty_access.carbon
index 405bf44f58da..242eab98734f 100644
--- a/toolchain/check/testdata/tuple/access/fail_empty_access.carbon
+++ b/toolchain/check/testdata/tuple/access/fail_empty_access.carbon
@@ -11,9 +11,10 @@
 fn F() {}
 
 fn Run() {
-  // CHECK:STDERR: fail_empty_access.carbon:[[@LINE+3]]:3: error: tuple element index `0` is past the end of type `()` [TupleIndexOutOfBounds]
+  // CHECK:STDERR: fail_empty_access.carbon:[[@LINE+4]]:3: error: tuple element index `0` is past the end of type `()` [TupleIndexOutOfBounds]
   // CHECK:STDERR:   F().0;
   // CHECK:STDERR:   ^~~~~
+  // CHECK:STDERR:
   F().0;
 }
 
@@ -56,8 +57,8 @@ fn Run() {
 // CHECK:STDOUT:   %F.ref: %F.type = name_ref F, file.%F.decl [template = constants.%F]
 // CHECK:STDOUT:   %F.call: init %empty_tuple.type = call %F.ref()
 // CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [template = constants.%int_0]
-// CHECK:STDOUT:   %.loc17_5.1: ref %empty_tuple.type = temporary_storage
-// CHECK:STDOUT:   %.loc17_5.2: ref %empty_tuple.type = temporary %.loc17_5.1, %F.call
+// CHECK:STDOUT:   %.loc18_5.1: ref %empty_tuple.type = temporary_storage
+// CHECK:STDOUT:   %.loc18_5.2: ref %empty_tuple.type = temporary %.loc18_5.1, %F.call
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/tuple/access/fail_large_index.carbon b/toolchain/check/testdata/tuple/access/fail_large_index.carbon
index b1ba74b54d58..2094a9815c45 100644
--- a/toolchain/check/testdata/tuple/access/fail_large_index.carbon
+++ b/toolchain/check/testdata/tuple/access/fail_large_index.carbon
@@ -15,9 +15,10 @@ var b: (i32,) = a;
 // CHECK:STDERR:              ^~~
 // CHECK:STDERR:
 var c: i32 = b.1;
-// CHECK:STDERR: fail_large_index.carbon:[[@LINE+3]]:14: error: tuple element index `2147483647` is past the end of type `(i32,)` [TupleIndexOutOfBounds]
+// CHECK:STDERR: fail_large_index.carbon:[[@LINE+4]]:14: error: tuple element index `2147483647` is past the end of type `(i32,)` [TupleIndexOutOfBounds]
 // CHECK:STDERR: var d: i32 = b.(0x7FFF_FFFF);
 // CHECK:STDERR:              ^~~~~~~~~~~~~~~
+// CHECK:STDERR:
 var d: i32 = b.(0x7FFF_FFFF);
 
 // CHECK:STDOUT: --- fail_large_index.carbon
@@ -89,7 +90,7 @@ var d: i32 = b.(0x7FFF_FFFF);
 // CHECK:STDOUT:   %b.ref.loc17: ref %tuple.type.a1c = name_ref b, file.%b
 // CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [template = constants.%int_1]
 // CHECK:STDOUT:   assign file.%c.var, <error>
-// CHECK:STDOUT:   %b.ref.loc21: ref %tuple.type.a1c = name_ref b, file.%b
+// CHECK:STDOUT:   %b.ref.loc22: ref %tuple.type.a1c = name_ref b, file.%b
 // CHECK:STDOUT:   %int_2147483647: Core.IntLiteral = int_value 2147483647 [template = constants.%int_2147483647]
 // CHECK:STDOUT:   assign file.%d.var, <error>
 // CHECK:STDOUT:   return
diff --git a/toolchain/check/testdata/tuple/access/fail_negative_indexing.carbon b/toolchain/check/testdata/tuple/access/fail_negative_indexing.carbon
index 0dfb78ae9048..4602f740fbf8 100644
--- a/toolchain/check/testdata/tuple/access/fail_negative_indexing.carbon
+++ b/toolchain/check/testdata/tuple/access/fail_negative_indexing.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/tuple/access/fail_negative_indexing.carbon
 
 var a: (i32, i32) = (12, 6);
-// CHECK:STDERR: fail_negative_indexing.carbon:[[@LINE+3]]:14: error: tuple element index `-10` is past the end of type `(i32, i32)` [TupleIndexOutOfBounds]
+// CHECK:STDERR: fail_negative_indexing.carbon:[[@LINE+4]]:14: error: tuple element index `-10` is past the end of type `(i32, i32)` [TupleIndexOutOfBounds]
 // CHECK:STDERR: var b: i32 = a.(-10);
 // CHECK:STDERR:              ^~~~~~~
+// CHECK:STDERR:
 var b: i32 = a.(-10);
 
 // CHECK:STDOUT: --- fail_negative_indexing.carbon
@@ -90,11 +91,11 @@ var b: i32 = a.(-10);
 // CHECK:STDOUT:   assign file.%a.var, %.loc11_28
 // CHECK:STDOUT:   %a.ref: ref %tuple.type.d07 = name_ref a, file.%a
 // CHECK:STDOUT:   %int_10: Core.IntLiteral = int_value 10 [template = constants.%int_10]
-// CHECK:STDOUT:   %impl.elem0.loc15: %Op.type.e42 = impl_witness_access constants.%impl_witness.0f6, element0 [template = constants.%Op.bba]
-// CHECK:STDOUT:   %Op.bound: <bound method> = bound_method %int_10, %impl.elem0.loc15 [template = constants.%Op.bound]
+// CHECK:STDOUT:   %impl.elem0.loc16: %Op.type.e42 = impl_witness_access constants.%impl_witness.0f6, element0 [template = constants.%Op.bba]
+// CHECK:STDOUT:   %Op.bound: <bound method> = bound_method %int_10, %impl.elem0.loc16 [template = constants.%Op.bound]
 // CHECK:STDOUT:   %int.snegate: init Core.IntLiteral = call %Op.bound(%int_10) [template = constants.%int_-10]
-// CHECK:STDOUT:   %.loc15_17.1: Core.IntLiteral = value_of_initializer %int.snegate [template = constants.%int_-10]
-// CHECK:STDOUT:   %.loc15_17.2: Core.IntLiteral = converted %int.snegate, %.loc15_17.1 [template = constants.%int_-10]
+// CHECK:STDOUT:   %.loc16_17.1: Core.IntLiteral = value_of_initializer %int.snegate [template = constants.%int_-10]
+// CHECK:STDOUT:   %.loc16_17.2: Core.IntLiteral = converted %int.snegate, %.loc16_17.1 [template = constants.%int_-10]
 // CHECK:STDOUT:   assign file.%b.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/tuple/access/fail_non_deterministic_type.carbon b/toolchain/check/testdata/tuple/access/fail_non_deterministic_type.carbon
index 1b779e1f3e3d..d2f83ba3e960 100644
--- a/toolchain/check/testdata/tuple/access/fail_non_deterministic_type.carbon
+++ b/toolchain/check/testdata/tuple/access/fail_non_deterministic_type.carbon
@@ -10,9 +10,10 @@
 
 var a: (i32, i32) = (2, 3);
 var b: i32 = 0;
-// CHECK:STDERR: fail_non_deterministic_type.carbon:[[@LINE+3]]:14: error: tuple index must be a constant [TupleIndexNotConstant]
+// CHECK:STDERR: fail_non_deterministic_type.carbon:[[@LINE+4]]:14: error: tuple index must be a constant [TupleIndexNotConstant]
 // CHECK:STDERR: var c: i32 = a.(b);
 // CHECK:STDERR:              ^~~~~
+// CHECK:STDERR:
 var c: i32 = a.(b);
 
 // CHECK:STDOUT: --- fail_non_deterministic_type.carbon
diff --git a/toolchain/check/testdata/tuple/access/fail_non_int_indexing.carbon b/toolchain/check/testdata/tuple/access/fail_non_int_indexing.carbon
index ba5ef9d4d05d..68f006fa0f29 100644
--- a/toolchain/check/testdata/tuple/access/fail_non_int_indexing.carbon
+++ b/toolchain/check/testdata/tuple/access/fail_non_int_indexing.carbon
@@ -9,12 +9,13 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/tuple/access/fail_non_int_indexing.carbon
 
 var a: (i32, i32) = (12, 6);
-// CHECK:STDERR: fail_non_int_indexing.carbon:[[@LINE+6]]:17: error: cannot implicitly convert from `f64` to `Core.IntLiteral` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_non_int_indexing.carbon:[[@LINE+7]]:17: error: cannot implicitly convert from `f64` to `Core.IntLiteral` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var b: i32 = a.(2.6);
 // CHECK:STDERR:                 ^~~
-// CHECK:STDERR: fail_non_int_indexing.carbon:[[@LINE+3]]:17: note: type `f64` does not implement interface `Core.ImplicitAs(Core.IntLiteral)` [MissingImplInMemberAccessNote]
+// CHECK:STDERR: fail_non_int_indexing.carbon:[[@LINE+4]]:17: note: type `f64` does not implement interface `Core.ImplicitAs(Core.IntLiteral)` [MissingImplInMemberAccessNote]
 // CHECK:STDERR: var b: i32 = a.(2.6);
 // CHECK:STDERR:                 ^~~
+// CHECK:STDERR:
 var b: i32 = a.(2.6);
 
 // CHECK:STDOUT: --- fail_non_int_indexing.carbon
@@ -86,7 +87,7 @@ var b: i32 = a.(2.6);
 // CHECK:STDOUT:   assign file.%a.var, %.loc11_28
 // CHECK:STDOUT:   %a.ref: ref %tuple.type.d07 = name_ref a, file.%a
 // CHECK:STDOUT:   %float: f64 = float_literal 2.6000000000000001 [template = constants.%float]
-// CHECK:STDOUT:   %.loc18: Core.IntLiteral = converted %float, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc19: Core.IntLiteral = converted %float, <error> [template = <error>]
 // CHECK:STDOUT:   assign file.%b.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/tuple/access/fail_non_tuple_access.carbon b/toolchain/check/testdata/tuple/access/fail_non_tuple_access.carbon
index dd2c745bd6fd..00c47afafe27 100644
--- a/toolchain/check/testdata/tuple/access/fail_non_tuple_access.carbon
+++ b/toolchain/check/testdata/tuple/access/fail_non_tuple_access.carbon
@@ -16,9 +16,10 @@ fn Main() {
   0[1];
 
   var non_tuple: [i32; 2] = (5, 5);
-  // CHECK:STDERR: fail_non_tuple_access.carbon:[[@LINE+3]]:20: error: type `[i32; 2]` does not support tuple indexing; only tuples can be indexed that way [TupleIndexOnANonTupleType]
+  // CHECK:STDERR: fail_non_tuple_access.carbon:[[@LINE+4]]:20: error: type `[i32; 2]` does not support tuple indexing; only tuples can be indexed that way [TupleIndexOnANonTupleType]
   // CHECK:STDERR:   var first: i32 = non_tuple.0;
   // CHECK:STDERR:                    ^~~~~~~~~~~
+  // CHECK:STDERR:
   var first: i32 = non_tuple.0;
 }
 
@@ -95,7 +96,7 @@ fn Main() {
 // CHECK:STDOUT:   %first.var: ref %i32 = var first
 // CHECK:STDOUT:   %first: ref %i32 = bind_name first, %first.var
 // CHECK:STDOUT:   %non_tuple.ref: ref %array_type = name_ref non_tuple, %non_tuple
-// CHECK:STDOUT:   %int_0.loc22: Core.IntLiteral = int_value 0 [template = constants.%int_0]
+// CHECK:STDOUT:   %int_0.loc23: Core.IntLiteral = int_value 0 [template = constants.%int_0]
 // CHECK:STDOUT:   assign %first.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/tuple/access/fail_out_of_bound_access.carbon b/toolchain/check/testdata/tuple/access/fail_out_of_bound_access.carbon
index 5f6b9fe953a7..b5e43a9ce202 100644
--- a/toolchain/check/testdata/tuple/access/fail_out_of_bound_access.carbon
+++ b/toolchain/check/testdata/tuple/access/fail_out_of_bound_access.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/tuple/access/fail_out_of_bound_access.carbon
 
 var a: (i32, i32) = (12, 6);
-// CHECK:STDERR: fail_out_of_bound_access.carbon:[[@LINE+3]]:14: error: tuple element index `2` is past the end of type `(i32, i32)` [TupleIndexOutOfBounds]
+// CHECK:STDERR: fail_out_of_bound_access.carbon:[[@LINE+4]]:14: error: tuple element index `2` is past the end of type `(i32, i32)` [TupleIndexOutOfBounds]
 // CHECK:STDERR: var b: i32 = a.2;
 // CHECK:STDERR:              ^~~
+// CHECK:STDERR:
 var b: i32 = a.2;
 
 // CHECK:STDOUT: --- fail_out_of_bound_access.carbon
diff --git a/toolchain/check/testdata/tuple/access/fail_out_of_bound_not_literal.carbon b/toolchain/check/testdata/tuple/access/fail_out_of_bound_not_literal.carbon
index 83c040c878a1..c5080197ca23 100644
--- a/toolchain/check/testdata/tuple/access/fail_out_of_bound_not_literal.carbon
+++ b/toolchain/check/testdata/tuple/access/fail_out_of_bound_not_literal.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/tuple/access/fail_out_of_bound_not_literal.carbon
 
 var a: (i32, i32) = (12, 34);
-// CHECK:STDERR: fail_out_of_bound_not_literal.carbon:[[@LINE+3]]:14: error: tuple element index `2` is past the end of type `(i32, i32)` [TupleIndexOutOfBounds]
+// CHECK:STDERR: fail_out_of_bound_not_literal.carbon:[[@LINE+4]]:14: error: tuple element index `2` is past the end of type `(i32, i32)` [TupleIndexOutOfBounds]
 // CHECK:STDERR: var b: i32 = a.({.index = 2}.index);
 // CHECK:STDERR:              ^~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 var b: i32 = a.({.index = 2}.index);
 
 // CHECK:STDOUT: --- fail_out_of_bound_not_literal.carbon
@@ -85,10 +86,10 @@ var b: i32 = a.({.index = 2}.index);
 // CHECK:STDOUT:   assign file.%a.var, %.loc11_29
 // CHECK:STDOUT:   %a.ref: ref %tuple.type.d07 = name_ref a, file.%a
 // CHECK:STDOUT:   %int_2: Core.IntLiteral = int_value 2 [template = constants.%int_2]
-// CHECK:STDOUT:   %.loc15_28.1: %struct_type.index = struct_literal (%int_2)
+// CHECK:STDOUT:   %.loc16_28.1: %struct_type.index = struct_literal (%int_2)
 // CHECK:STDOUT:   %struct: %struct_type.index = struct_value (%int_2) [template = constants.%struct]
-// CHECK:STDOUT:   %.loc15_28.2: %struct_type.index = converted %.loc15_28.1, %struct [template = constants.%struct]
-// CHECK:STDOUT:   %.loc15_29: Core.IntLiteral = struct_access %.loc15_28.2, element0 [template = constants.%int_2]
+// CHECK:STDOUT:   %.loc16_28.2: %struct_type.index = converted %.loc16_28.1, %struct [template = constants.%struct]
+// CHECK:STDOUT:   %.loc16_29: Core.IntLiteral = struct_access %.loc16_28.2, element0 [template = constants.%int_2]
 // CHECK:STDOUT:   assign file.%b.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/tuple/fail_assign_nested.carbon b/toolchain/check/testdata/tuple/fail_assign_nested.carbon
index 6ed017c0d30c..d67a5fe9c44d 100644
--- a/toolchain/check/testdata/tuple/fail_assign_nested.carbon
+++ b/toolchain/check/testdata/tuple/fail_assign_nested.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/tuple/fail_assign_nested.carbon
 
-// CHECK:STDERR: fail_assign_nested.carbon:[[@LINE+3]]:36: error: cannot initialize tuple of 2 elements from tuple with 3 elements [TupleInitElementCountMismatch]
+// CHECK:STDERR: fail_assign_nested.carbon:[[@LINE+4]]:36: error: cannot initialize tuple of 2 elements from tuple with 3 elements [TupleInitElementCountMismatch]
 // CHECK:STDERR: var x: ((i32, i32), (i32, i32)) = ((1, 2, 3), (4, 5, 6));
 // CHECK:STDERR:                                    ^~~~~~~~~
+// CHECK:STDERR:
 var x: ((i32, i32), (i32, i32)) = ((1, 2, 3), (4, 5, 6));
 
 // CHECK:STDOUT: --- fail_assign_nested.carbon
@@ -53,12 +54,12 @@ var x: ((i32, i32), (i32, i32)) = ((1, 2, 3), (4, 5, 6));
 // CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [template = constants.%int_1]
 // CHECK:STDOUT:   %int_2: Core.IntLiteral = int_value 2 [template = constants.%int_2]
 // CHECK:STDOUT:   %int_3: Core.IntLiteral = int_value 3 [template = constants.%int_3]
-// CHECK:STDOUT:   %.loc14_44: %tuple.type.37f = tuple_literal (%int_1, %int_2, %int_3)
+// CHECK:STDOUT:   %.loc15_44: %tuple.type.37f = tuple_literal (%int_1, %int_2, %int_3)
 // CHECK:STDOUT:   %int_4: Core.IntLiteral = int_value 4 [template = constants.%int_4]
 // CHECK:STDOUT:   %int_5: Core.IntLiteral = int_value 5 [template = constants.%int_5]
 // CHECK:STDOUT:   %int_6: Core.IntLiteral = int_value 6 [template = constants.%int_6]
-// CHECK:STDOUT:   %.loc14_55: %tuple.type.37f = tuple_literal (%int_4, %int_5, %int_6)
-// CHECK:STDOUT:   %.loc14_56: %tuple.type.e89 = tuple_literal (%.loc14_44, %.loc14_55)
+// CHECK:STDOUT:   %.loc15_55: %tuple.type.37f = tuple_literal (%int_4, %int_5, %int_6)
+// CHECK:STDOUT:   %.loc15_56: %tuple.type.e89 = tuple_literal (%.loc15_44, %.loc15_55)
 // CHECK:STDOUT:   assign file.%x.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/tuple/fail_element_type_mismatch.carbon b/toolchain/check/testdata/tuple/fail_element_type_mismatch.carbon
index fc0d41e4f000..8a1a829e6d6a 100644
--- a/toolchain/check/testdata/tuple/fail_element_type_mismatch.carbon
+++ b/toolchain/check/testdata/tuple/fail_element_type_mismatch.carbon
@@ -8,12 +8,13 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/tuple/fail_element_type_mismatch.carbon
 
-// CHECK:STDERR: fail_element_type_mismatch.carbon:[[@LINE+6]]:21: error: cannot implicitly convert from `f64` to `i32` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_element_type_mismatch.carbon:[[@LINE+7]]:21: error: cannot implicitly convert from `f64` to `i32` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var x: (i32, i32) = (2, 65.89);
 // CHECK:STDERR:                     ^~~~~~~~~~
-// CHECK:STDERR: fail_element_type_mismatch.carbon:[[@LINE+3]]:21: note: type `f64` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]
+// CHECK:STDERR: fail_element_type_mismatch.carbon:[[@LINE+4]]:21: note: type `f64` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]
 // CHECK:STDERR: var x: (i32, i32) = (2, 65.89);
 // CHECK:STDERR:                     ^~~~~~~~~~
+// CHECK:STDERR:
 var x: (i32, i32) = (2, 65.89);
 
 // CHECK:STDOUT: --- fail_element_type_mismatch.carbon
@@ -57,15 +58,15 @@ var x: (i32, i32) = (2, 65.89);
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %int_2: Core.IntLiteral = int_value 2 [template = constants.%int_2.ecc]
 // CHECK:STDOUT:   %float: f64 = float_literal 65.890000000000001 [template = constants.%float]
-// CHECK:STDOUT:   %.loc17_30.1: %tuple.type.2c1 = tuple_literal (%int_2, %float)
+// CHECK:STDOUT:   %.loc18_30.1: %tuple.type.2c1 = tuple_literal (%int_2, %float)
 // CHECK:STDOUT:   %impl.elem0: %Convert.type.1b6 = impl_witness_access constants.%impl_witness.d39, element0 [template = constants.%Convert.956]
 // CHECK:STDOUT:   %Convert.bound: <bound method> = bound_method %int_2, %impl.elem0 [template = constants.%Convert.bound]
 // CHECK:STDOUT:   %Convert.specific_fn: <specific function> = specific_function %Convert.bound, @Convert.2(constants.%int_32) [template = constants.%Convert.specific_fn]
 // CHECK:STDOUT:   %int.convert_checked: init %i32 = call %Convert.specific_fn(%int_2) [template = constants.%int_2.ef8]
-// CHECK:STDOUT:   %.loc17_30.2: init %i32 = converted %int_2, %int.convert_checked [template = constants.%int_2.ef8]
+// CHECK:STDOUT:   %.loc18_30.2: init %i32 = converted %int_2, %int.convert_checked [template = constants.%int_2.ef8]
 // CHECK:STDOUT:   %tuple.elem0: ref %i32 = tuple_access file.%x.var, element0
-// CHECK:STDOUT:   %.loc17_30.3: init %i32 = initialize_from %.loc17_30.2 to %tuple.elem0 [template = constants.%int_2.ef8]
-// CHECK:STDOUT:   %.loc17_30.4: %i32 = converted %float, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc18_30.3: init %i32 = initialize_from %.loc18_30.2 to %tuple.elem0 [template = constants.%int_2.ef8]
+// CHECK:STDOUT:   %.loc18_30.4: %i32 = converted %float, <error> [template = <error>]
 // CHECK:STDOUT:   assign file.%x.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/tuple/fail_nested_incomplete.carbon b/toolchain/check/testdata/tuple/fail_nested_incomplete.carbon
index aa2a2d71fb27..ceeef727464d 100644
--- a/toolchain/check/testdata/tuple/fail_nested_incomplete.carbon
+++ b/toolchain/check/testdata/tuple/fail_nested_incomplete.carbon
@@ -10,12 +10,13 @@
 
 class Incomplete;
 
-// CHECK:STDERR: fail_nested_incomplete.carbon:[[@LINE+6]]:8: error: variable has incomplete type `(i32, Incomplete)` [IncompleteTypeInVarDecl]
+// CHECK:STDERR: fail_nested_incomplete.carbon:[[@LINE+7]]:8: error: variable has incomplete type `(i32, Incomplete)` [IncompleteTypeInVarDecl]
 // CHECK:STDERR: var t: (i32, Incomplete);
 // CHECK:STDERR:        ^~~~~~~~~~~~~~~~~
 // CHECK:STDERR: fail_nested_incomplete.carbon:[[@LINE-5]]:1: note: class was forward declared here [ClassForwardDeclaredHere]
 // CHECK:STDERR: class Incomplete;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 var t: (i32, Incomplete);
 
 var p: Incomplete* = &t[1];
diff --git a/toolchain/check/testdata/tuple/fail_too_few_element.carbon b/toolchain/check/testdata/tuple/fail_too_few_element.carbon
index 57d68ea09902..9fcd7e324a8f 100644
--- a/toolchain/check/testdata/tuple/fail_too_few_element.carbon
+++ b/toolchain/check/testdata/tuple/fail_too_few_element.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/tuple/fail_too_few_element.carbon
 
-// CHECK:STDERR: fail_too_few_element.carbon:[[@LINE+3]]:21: error: cannot initialize tuple of 2 elements from tuple with 1 element [TupleInitElementCountMismatch]
+// CHECK:STDERR: fail_too_few_element.carbon:[[@LINE+4]]:21: error: cannot initialize tuple of 2 elements from tuple with 1 element [TupleInitElementCountMismatch]
 // CHECK:STDERR: var x: (i32, i32) = (2, );
 // CHECK:STDERR:                     ^~~~~
+// CHECK:STDERR:
 var x: (i32, i32) = (2, );
 
 // CHECK:STDOUT: --- fail_too_few_element.carbon
@@ -44,7 +45,7 @@ var x: (i32, i32) = (2, );
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %int_2: Core.IntLiteral = int_value 2 [template = constants.%int_2]
-// CHECK:STDOUT:   %.loc14: %tuple.type.985 = tuple_literal (%int_2)
+// CHECK:STDOUT:   %.loc15: %tuple.type.985 = tuple_literal (%int_2)
 // CHECK:STDOUT:   assign file.%x.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/tuple/fail_type_assign.carbon b/toolchain/check/testdata/tuple/fail_type_assign.carbon
index e6702bb1d973..150f07860f01 100644
--- a/toolchain/check/testdata/tuple/fail_type_assign.carbon
+++ b/toolchain/check/testdata/tuple/fail_type_assign.carbon
@@ -8,12 +8,13 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/tuple/fail_type_assign.carbon
 
-// CHECK:STDERR: fail_type_assign.carbon:[[@LINE+6]]:18: error: cannot implicitly convert from `type` to `i32` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_type_assign.carbon:[[@LINE+7]]:18: error: cannot implicitly convert from `type` to `i32` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var x: (i32, ) = (i32, );
 // CHECK:STDERR:                  ^~~~~~~
-// CHECK:STDERR: fail_type_assign.carbon:[[@LINE+3]]:18: note: type `type` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]
+// CHECK:STDERR: fail_type_assign.carbon:[[@LINE+4]]:18: note: type `type` does not implement interface `Core.ImplicitAs(i32)` [MissingImplInMemberAccessNote]
 // CHECK:STDERR: var x: (i32, ) = (i32, );
 // CHECK:STDERR:                  ^~~~~~~
+// CHECK:STDERR:
 var x: (i32, ) = (i32, );
 
 // CHECK:STDOUT: --- fail_type_assign.carbon
@@ -48,8 +49,8 @@ var x: (i32, ) = (i32, );
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [template = constants.%int_32]
 // CHECK:STDOUT:   %i32: type = class_type @Int, @Int(constants.%int_32) [template = constants.%i32]
-// CHECK:STDOUT:   %.loc17_24.1: %tuple.type.85c = tuple_literal (%i32)
-// CHECK:STDOUT:   %.loc17_24.2: %i32 = converted %i32, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc18_24.1: %tuple.type.85c = tuple_literal (%i32)
+// CHECK:STDOUT:   %.loc18_24.2: %i32 = converted %i32, <error> [template = <error>]
 // CHECK:STDOUT:   assign file.%x.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/tuple/fail_value_as_type.carbon b/toolchain/check/testdata/tuple/fail_value_as_type.carbon
index 3b231e5d88f4..760d5ac75b7c 100644
--- a/toolchain/check/testdata/tuple/fail_value_as_type.carbon
+++ b/toolchain/check/testdata/tuple/fail_value_as_type.carbon
@@ -8,12 +8,13 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/tuple/fail_value_as_type.carbon
 
-// CHECK:STDERR: fail_value_as_type.carbon:[[@LINE+6]]:8: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_value_as_type.carbon:[[@LINE+7]]:8: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var x: (1, );
 // CHECK:STDERR:        ^~~~~
-// CHECK:STDERR: fail_value_as_type.carbon:[[@LINE+3]]:8: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
+// CHECK:STDERR: fail_value_as_type.carbon:[[@LINE+4]]:8: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
 // CHECK:STDERR: var x: (1, );
 // CHECK:STDERR:        ^~~~~
+// CHECK:STDERR:
 var x: (1, );
 
 // CHECK:STDOUT: --- fail_value_as_type.carbon
diff --git a/toolchain/check/testdata/tuple/import.carbon b/toolchain/check/testdata/tuple/import.carbon
index 1b7c1e20c901..5063de368ca5 100644
--- a/toolchain/check/testdata/tuple/import.carbon
+++ b/toolchain/check/testdata/tuple/import.carbon
@@ -45,12 +45,13 @@ var c_bad: C((1, 2, 3)) = F();
 
 impl package Implicit;
 
-// CHECK:STDERR: fail_bad_value.impl.carbon:[[@LINE+6]]:1: error: cannot implicitly convert from `C((1, 2))` to `C((3, 4))` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_bad_value.impl.carbon:[[@LINE+7]]:1: error: cannot implicitly convert from `C((1, 2))` to `C((3, 4))` [ImplicitAsConversionFailure]
 // CHECK:STDERR: var c_bad: C((3, 4)) = F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_bad_value.impl.carbon:[[@LINE+3]]:1: note: type `C((1, 2))` does not implement interface `Core.ImplicitAs(C((3, 4)))` [MissingImplInMemberAccessNote]
+// CHECK:STDERR: fail_bad_value.impl.carbon:[[@LINE+4]]:1: note: type `C((1, 2))` does not implement interface `Core.ImplicitAs(C((3, 4)))` [MissingImplInMemberAccessNote]
 // CHECK:STDERR: var c_bad: C((3, 4)) = F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 var c_bad: C((3, 4)) = F();
 
 // CHECK:STDOUT: --- implicit.carbon
@@ -535,9 +536,9 @@ var c_bad: C((3, 4)) = F();
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %F.ref: %F.type = name_ref F, imports.%import_ref.b37 [template = constants.%F]
-// CHECK:STDOUT:   %.loc10_26: ref %C.cf0 = temporary_storage
-// CHECK:STDOUT:   %F.call: init %C.cf0 = call %F.ref() to %.loc10_26
-// CHECK:STDOUT:   %.loc10_27: %C.ed5 = converted %F.call, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc11_26: ref %C.cf0 = temporary_storage
+// CHECK:STDOUT:   %F.call: init %C.cf0 = call %F.ref() to %.loc11_26
+// CHECK:STDOUT:   %.loc11_27: %C.ed5 = converted %F.call, <error> [template = <error>]
 // CHECK:STDOUT:   assign file.%c_bad.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/tuple/no_prelude/fail_assign_empty.carbon b/toolchain/check/testdata/tuple/no_prelude/fail_assign_empty.carbon
index df8abdb34dd2..81e5d3429562 100644
--- a/toolchain/check/testdata/tuple/no_prelude/fail_assign_empty.carbon
+++ b/toolchain/check/testdata/tuple/no_prelude/fail_assign_empty.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/tuple/no_prelude/fail_assign_empty.carbon
 
-// CHECK:STDERR: fail_assign_empty.carbon:[[@LINE+3]]:16: error: cannot initialize tuple of 1 element from tuple with 0 elements [TupleInitElementCountMismatch]
+// CHECK:STDERR: fail_assign_empty.carbon:[[@LINE+4]]:16: error: cannot initialize tuple of 1 element from tuple with 0 elements [TupleInitElementCountMismatch]
 // CHECK:STDERR: var x: ((),) = ();
 // CHECK:STDERR:                ^~
+// CHECK:STDERR:
 var x: ((),) = ();
 
 // CHECK:STDOUT: --- fail_assign_empty.carbon
@@ -30,7 +31,7 @@ var x: ((),) = ();
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %.loc14: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:   %.loc15: %empty_tuple.type = tuple_literal ()
 // CHECK:STDOUT:   assign file.%x.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/tuple/no_prelude/fail_assign_to_empty.carbon b/toolchain/check/testdata/tuple/no_prelude/fail_assign_to_empty.carbon
index 434a52a04221..8ccf40a6bfdb 100644
--- a/toolchain/check/testdata/tuple/no_prelude/fail_assign_to_empty.carbon
+++ b/toolchain/check/testdata/tuple/no_prelude/fail_assign_to_empty.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/tuple/no_prelude/fail_assign_to_empty.carbon
 
-// CHECK:STDERR: fail_assign_to_empty.carbon:[[@LINE+3]]:13: error: cannot initialize tuple of 0 elements from tuple with 1 element [TupleInitElementCountMismatch]
+// CHECK:STDERR: fail_assign_to_empty.carbon:[[@LINE+4]]:13: error: cannot initialize tuple of 0 elements from tuple with 1 element [TupleInitElementCountMismatch]
 // CHECK:STDERR: var x: () = ((),);
 // CHECK:STDERR:             ^~~~~
+// CHECK:STDERR:
 var x: () = ((),);
 
 // CHECK:STDOUT: --- fail_assign_to_empty.carbon
@@ -30,8 +31,8 @@ var x: () = ((),);
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %.loc14_15: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:   %.loc14_17: %tuple.type = tuple_literal (%.loc14_15)
+// CHECK:STDOUT:   %.loc15_15: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:   %.loc15_17: %tuple.type = tuple_literal (%.loc15_15)
 // CHECK:STDOUT:   assign file.%x.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/var/fail_not_copyable.carbon b/toolchain/check/testdata/var/fail_not_copyable.carbon
index 723f4aee0ebd..fcf2f5039ea4 100644
--- a/toolchain/check/testdata/var/fail_not_copyable.carbon
+++ b/toolchain/check/testdata/var/fail_not_copyable.carbon
@@ -21,9 +21,10 @@ fn F(x: X) {
   var s: String = "hello";
 
   // TODO: Decide on rules for when classes are copyable.
-  // CHECK:STDERR: fail_not_copyable.carbon:[[@LINE+3]]:14: error: cannot copy value of type `X` [CopyOfUncopyableType]
+  // CHECK:STDERR: fail_not_copyable.carbon:[[@LINE+4]]:14: error: cannot copy value of type `X` [CopyOfUncopyableType]
   // CHECK:STDERR:   var y: X = x;
   // CHECK:STDERR:              ^
+  // CHECK:STDERR:
   var y: X = x;
 }
 
diff --git a/toolchain/check/testdata/var/fail_storage_is_literal.carbon b/toolchain/check/testdata/var/fail_storage_is_literal.carbon
index eb8135674134..b4e70ceac6e8 100644
--- a/toolchain/check/testdata/var/fail_storage_is_literal.carbon
+++ b/toolchain/check/testdata/var/fail_storage_is_literal.carbon
@@ -9,12 +9,13 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/fail_storage_is_literal.carbon
 
 fn Main() {
-  // CHECK:STDERR: fail_storage_is_literal.carbon:[[@LINE+6]]:10: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_storage_is_literal.carbon:[[@LINE+7]]:10: error: cannot implicitly convert from `Core.IntLiteral` to `type` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   var x: 1 = 1;
   // CHECK:STDERR:          ^
-  // CHECK:STDERR: fail_storage_is_literal.carbon:[[@LINE+3]]:10: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR: fail_storage_is_literal.carbon:[[@LINE+4]]:10: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(type)` [MissingImplInMemberAccessNote]
   // CHECK:STDERR:   var x: 1 = 1;
   // CHECK:STDERR:          ^
+  // CHECK:STDERR:
   var x: 1 = 1;
 }
 
diff --git a/toolchain/check/testdata/var/fail_todo_control_flow_init.carbon b/toolchain/check/testdata/var/fail_todo_control_flow_init.carbon
index 1ff104e55f72..d877a962765b 100644
--- a/toolchain/check/testdata/var/fail_todo_control_flow_init.carbon
+++ b/toolchain/check/testdata/var/fail_todo_control_flow_init.carbon
@@ -58,17 +58,18 @@ var x2: () = if false then () else ();
 // CHECK:STDERR:
 var y: bool = true or false;
 
-// CHECK:STDERR: fail_todo_control_flow_init.carbon:[[@LINE+11]]:16: error: semantics TODO: `Control flow expressions are currently only supported inside functions.` [SemanticsTodo]
+// CHECK:STDERR: fail_todo_control_flow_init.carbon:[[@LINE+12]]:16: error: semantics TODO: `Control flow expressions are currently only supported inside functions.` [SemanticsTodo]
 // CHECK:STDERR: var y2: bool = false or true;
 // CHECK:STDERR:                ^~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_todo_control_flow_init.carbon:[[@LINE+7]]:16: error: semantics TODO: `Control flow expressions are currently only supported inside functions.` [SemanticsTodo]
+// CHECK:STDERR: fail_todo_control_flow_init.carbon:[[@LINE+8]]:16: error: semantics TODO: `Control flow expressions are currently only supported inside functions.` [SemanticsTodo]
 // CHECK:STDERR: var y2: bool = false or true;
 // CHECK:STDERR:                ^~~~~~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_todo_control_flow_init.carbon:[[@LINE+3]]:16: error: semantics TODO: `Control flow expressions are currently only supported inside functions.` [SemanticsTodo]
+// CHECK:STDERR: fail_todo_control_flow_init.carbon:[[@LINE+4]]:16: error: semantics TODO: `Control flow expressions are currently only supported inside functions.` [SemanticsTodo]
 // CHECK:STDERR: var y2: bool = false or true;
 // CHECK:STDERR:                ^~~~~~~~~~~~~
+// CHECK:STDERR:
 var y2: bool = false or true;
 
 // CHECK:STDOUT: --- fail_todo_control_flow_init.carbon
diff --git a/toolchain/check/testdata/var/no_prelude/export_name.carbon b/toolchain/check/testdata/var/no_prelude/export_name.carbon
index e1bb7077ea99..a07b8eab4e4a 100644
--- a/toolchain/check/testdata/var/no_prelude/export_name.carbon
+++ b/toolchain/check/testdata/var/no_prelude/export_name.carbon
@@ -34,11 +34,12 @@ export v;
 
 library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_todo_use_export.carbon:[[@LINE+5]]:1: in import [InImport]
+// CHECK:STDERR: fail_todo_use_export.carbon:[[@LINE+6]]:1: in import [InImport]
 // CHECK:STDERR: export.carbon:4:1: in import [InImport]
 // CHECK:STDERR: base.carbon:4:5: error: semantics TODO: `Non-constant ImportRefLoaded (comes up with var)` [SemanticsTodo]
 // CHECK:STDERR: var v: ();
 // CHECK:STDERR:     ^
+// CHECK:STDERR:
 import library "export";
 
 var w: () = v;
@@ -99,9 +100,9 @@ var w: () = v;
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %v.ref: ref %empty_tuple.type = name_ref v, imports.%import_ref [template = <error>]
-// CHECK:STDOUT:   %.loc11_13: init %empty_tuple.type = tuple_init () to file.%w.var [template = constants.%empty_tuple]
-// CHECK:STDOUT:   %.loc11_14: init %empty_tuple.type = converted %v.ref, %.loc11_13 [template = constants.%empty_tuple]
-// CHECK:STDOUT:   assign file.%w.var, %.loc11_14
+// CHECK:STDOUT:   %.loc12_13: init %empty_tuple.type = tuple_init () to file.%w.var [template = constants.%empty_tuple]
+// CHECK:STDOUT:   %.loc12_14: init %empty_tuple.type = converted %v.ref, %.loc12_13 [template = constants.%empty_tuple]
+// CHECK:STDOUT:   assign file.%w.var, %.loc12_14
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/var/no_prelude/fail_duplicate_decl.carbon b/toolchain/check/testdata/var/no_prelude/fail_duplicate_decl.carbon
index 416fbecd9a25..a826201b77f5 100644
--- a/toolchain/check/testdata/var/no_prelude/fail_duplicate_decl.carbon
+++ b/toolchain/check/testdata/var/no_prelude/fail_duplicate_decl.carbon
@@ -11,12 +11,13 @@
 
 fn Main() {
   var x: () = ();
-  // CHECK:STDERR: fail_duplicate_decl.carbon:[[@LINE+6]]:7: error: duplicate name being declared in the same scope [NameDeclDuplicate]
+  // CHECK:STDERR: fail_duplicate_decl.carbon:[[@LINE+7]]:7: error: duplicate name being declared in the same scope [NameDeclDuplicate]
   // CHECK:STDERR:   var x: () = ();
   // CHECK:STDERR:       ^
   // CHECK:STDERR: fail_duplicate_decl.carbon:[[@LINE-4]]:7: note: name is previously declared here [NameDeclPrevious]
   // CHECK:STDERR:   var x: () = ();
   // CHECK:STDERR:       ^
+  // CHECK:STDERR:
   var x: () = ();
 }
 
@@ -44,12 +45,12 @@ fn Main() {
 // CHECK:STDOUT:   %.loc13_16.2: init %empty_tuple.type = tuple_init () to %x.var.loc13 [template = constants.%empty_tuple]
 // CHECK:STDOUT:   %.loc13_17: init %empty_tuple.type = converted %.loc13_16.1, %.loc13_16.2 [template = constants.%empty_tuple]
 // CHECK:STDOUT:   assign %x.var.loc13, %.loc13_17
-// CHECK:STDOUT:   %x.var.loc20: ref %empty_tuple.type = var x
-// CHECK:STDOUT:   %x.loc20: ref %empty_tuple.type = bind_name x, %x.var.loc20
-// CHECK:STDOUT:   %.loc20_16.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:   %.loc20_16.2: init %empty_tuple.type = tuple_init () to %x.var.loc20 [template = constants.%empty_tuple]
-// CHECK:STDOUT:   %.loc20_17: init %empty_tuple.type = converted %.loc20_16.1, %.loc20_16.2 [template = constants.%empty_tuple]
-// CHECK:STDOUT:   assign %x.var.loc20, %.loc20_17
+// CHECK:STDOUT:   %x.var.loc21: ref %empty_tuple.type = var x
+// CHECK:STDOUT:   %x.loc21: ref %empty_tuple.type = bind_name x, %x.var.loc21
+// CHECK:STDOUT:   %.loc21_16.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:   %.loc21_16.2: init %empty_tuple.type = tuple_init () to %x.var.loc21 [template = constants.%empty_tuple]
+// CHECK:STDOUT:   %.loc21_17: init %empty_tuple.type = converted %.loc21_16.1, %.loc21_16.2 [template = constants.%empty_tuple]
+// CHECK:STDOUT:   assign %x.var.loc21, %.loc21_17
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/var/no_prelude/fail_generic.carbon b/toolchain/check/testdata/var/no_prelude/fail_generic.carbon
index 89f7994de283..74a1b60d09ef 100644
--- a/toolchain/check/testdata/var/no_prelude/fail_generic.carbon
+++ b/toolchain/check/testdata/var/no_prelude/fail_generic.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/no_prelude/fail_generic.carbon
 
 fn Main() {
-  // CHECK:STDERR: fail_generic.carbon:[[@LINE+3]]:11: error: `var` declaration cannot declare a compile-time binding [CompileTimeBindingInVarDecl]
+  // CHECK:STDERR: fail_generic.carbon:[[@LINE+4]]:11: error: `var` declaration cannot declare a compile-time binding [CompileTimeBindingInVarDecl]
   // CHECK:STDERR:   var x:! () = ();
   // CHECK:STDERR:           ^~
+  // CHECK:STDERR:
   var x:! () = ();
 }
 
@@ -36,10 +37,10 @@ fn Main() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %x.var: ref %empty_tuple.type = var x
 // CHECK:STDOUT:   %x: %empty_tuple.type = bind_symbolic_name x, %x.var [symbolic = constants.%x]
-// CHECK:STDOUT:   %.loc15_17.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:   %.loc15_17.2: init %empty_tuple.type = tuple_init () to %x.var [template = constants.%empty_tuple]
-// CHECK:STDOUT:   %.loc15_18: init %empty_tuple.type = converted %.loc15_17.1, %.loc15_17.2 [template = constants.%empty_tuple]
-// CHECK:STDOUT:   assign %x.var, %.loc15_18
+// CHECK:STDOUT:   %.loc16_17.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:   %.loc16_17.2: init %empty_tuple.type = tuple_init () to %x.var [template = constants.%empty_tuple]
+// CHECK:STDOUT:   %.loc16_18: init %empty_tuple.type = converted %.loc16_17.1, %.loc16_17.2 [template = constants.%empty_tuple]
+// CHECK:STDOUT:   assign %x.var, %.loc16_18
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/var/no_prelude/fail_init_type_mismatch.carbon b/toolchain/check/testdata/var/no_prelude/fail_init_type_mismatch.carbon
index 1c3b26c90a02..6006cc924cf2 100644
--- a/toolchain/check/testdata/var/no_prelude/fail_init_type_mismatch.carbon
+++ b/toolchain/check/testdata/var/no_prelude/fail_init_type_mismatch.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/no_prelude/fail_init_type_mismatch.carbon
 
 fn Main() {
-  // CHECK:STDERR: fail_init_type_mismatch.carbon:[[@LINE+3]]:3: error: `Core.ImplicitAs` implicitly referenced here, but package `Core` not found [CoreNotFound]
+  // CHECK:STDERR: fail_init_type_mismatch.carbon:[[@LINE+4]]:3: error: `Core.ImplicitAs` implicitly referenced here, but package `Core` not found [CoreNotFound]
   // CHECK:STDERR:   var x: {} = ();
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   var x: {} = ();
 }
 
@@ -36,10 +37,10 @@ fn Main() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %x.var: ref %empty_struct_type = var x
 // CHECK:STDOUT:   %x: ref %empty_struct_type = bind_name x, %x.var
-// CHECK:STDOUT:   %.loc15_16.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:   %.loc16_16.1: %empty_tuple.type = tuple_literal ()
 // CHECK:STDOUT:   %empty_tuple: %empty_tuple.type = tuple_value () [template = constants.%empty_tuple]
-// CHECK:STDOUT:   %.loc15_16.2: %empty_tuple.type = converted %.loc15_16.1, %empty_tuple [template = constants.%empty_tuple]
-// CHECK:STDOUT:   %.loc15_17: %empty_struct_type = converted %.loc15_16.1, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc16_16.2: %empty_tuple.type = converted %.loc16_16.1, %empty_tuple [template = constants.%empty_tuple]
+// CHECK:STDOUT:   %.loc16_17: %empty_struct_type = converted %.loc16_16.1, <error> [template = <error>]
 // CHECK:STDOUT:   assign %x.var, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/var/no_prelude/fail_init_with_self.carbon b/toolchain/check/testdata/var/no_prelude/fail_init_with_self.carbon
index 72c4c49de971..dfb4c6864539 100644
--- a/toolchain/check/testdata/var/no_prelude/fail_init_with_self.carbon
+++ b/toolchain/check/testdata/var/no_prelude/fail_init_with_self.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/no_prelude/fail_init_with_self.carbon
 
 fn Main() {
-  // CHECK:STDERR: fail_init_with_self.carbon:[[@LINE+3]]:15: error: name `x` not found [NameNotFound]
+  // CHECK:STDERR: fail_init_with_self.carbon:[[@LINE+4]]:15: error: name `x` not found [NameNotFound]
   // CHECK:STDERR:   var x: () = x;
   // CHECK:STDERR:               ^
+  // CHECK:STDERR:
   var x: () = x;
 }
 
diff --git a/toolchain/check/testdata/var/no_prelude/fail_lookup_outside_scope.carbon b/toolchain/check/testdata/var/no_prelude/fail_lookup_outside_scope.carbon
index e1ddf6f028a9..50ddc7155cdc 100644
--- a/toolchain/check/testdata/var/no_prelude/fail_lookup_outside_scope.carbon
+++ b/toolchain/check/testdata/var/no_prelude/fail_lookup_outside_scope.carbon
@@ -12,9 +12,10 @@ fn Main() {
   var x: ();
 }
 
-// CHECK:STDERR: fail_lookup_outside_scope.carbon:[[@LINE+3]]:13: error: name `x` not found [NameNotFound]
+// CHECK:STDERR: fail_lookup_outside_scope.carbon:[[@LINE+4]]:13: error: name `x` not found [NameNotFound]
 // CHECK:STDERR: var y: () = x;
 // CHECK:STDERR:             ^
+// CHECK:STDERR:
 var y: () = x;
 
 // CHECK:STDOUT: --- fail_lookup_outside_scope.carbon
diff --git a/toolchain/check/testdata/var/no_prelude/fail_modifiers.carbon b/toolchain/check/testdata/var/no_prelude/fail_modifiers.carbon
index 510e6b0b7c7f..ff306ff4896f 100644
--- a/toolchain/check/testdata/var/no_prelude/fail_modifiers.carbon
+++ b/toolchain/check/testdata/var/no_prelude/fail_modifiers.carbon
@@ -36,9 +36,10 @@ private protected var c: ();
 // CHECK:STDERR:
 protected protected var d: ();
 
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+3]]:1: error: `abstract` not allowed on `var` declaration [ModifierNotAllowedOnDeclaration]
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+4]]:1: error: `abstract` not allowed on `var` declaration [ModifierNotAllowedOnDeclaration]
 // CHECK:STDERR: abstract var e: ();
 // CHECK:STDERR: ^~~~~~~~
+// CHECK:STDERR:
 abstract var e: ();
 
 // CHECK:STDOUT: --- fail_modifiers.carbon
diff --git a/toolchain/check/testdata/var/no_prelude/fail_namespace_conflict.carbon b/toolchain/check/testdata/var/no_prelude/fail_namespace_conflict.carbon
index 9c790d7c2d59..5bd94df11e66 100644
--- a/toolchain/check/testdata/var/no_prelude/fail_namespace_conflict.carbon
+++ b/toolchain/check/testdata/var/no_prelude/fail_namespace_conflict.carbon
@@ -19,12 +19,13 @@ namespace A;
 // CHECK:STDERR:
 var A: ();
 
-// CHECK:STDERR: fail_namespace_conflict.carbon:[[@LINE+6]]:5: error: duplicate name being declared in the same scope [NameDeclDuplicate]
+// CHECK:STDERR: fail_namespace_conflict.carbon:[[@LINE+7]]:5: error: duplicate name being declared in the same scope [NameDeclDuplicate]
 // CHECK:STDERR: var A: () = ();
 // CHECK:STDERR:     ^
 // CHECK:STDERR: fail_namespace_conflict.carbon:[[@LINE-14]]:1: note: name is previously declared here [NameDeclPrevious]
 // CHECK:STDERR: namespace A;
 // CHECK:STDERR: ^~~~~~~~~~~~
+// CHECK:STDERR:
 var A: () = ();
 
 // CHECK:STDOUT: --- fail_namespace_conflict.carbon
@@ -41,16 +42,16 @@ var A: () = ();
 // CHECK:STDOUT:   %A.loc11: <namespace> = namespace [template] {}
 // CHECK:STDOUT:   %A.var.loc20: ref %empty_tuple.type = var A
 // CHECK:STDOUT:   %A.loc20: ref %empty_tuple.type = bind_name A, %A.var.loc20
-// CHECK:STDOUT:   %A.var.loc28: ref %empty_tuple.type = var A
-// CHECK:STDOUT:   %A.loc28: ref %empty_tuple.type = bind_name A, %A.var.loc28
+// CHECK:STDOUT:   %A.var.loc29: ref %empty_tuple.type = var A
+// CHECK:STDOUT:   %A.loc29: ref %empty_tuple.type = bind_name A, %A.var.loc29
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %.loc28_14.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:   %.loc28_14.2: init %empty_tuple.type = tuple_init () to file.%A.var.loc28 [template = constants.%empty_tuple]
-// CHECK:STDOUT:   %.loc28_15: init %empty_tuple.type = converted %.loc28_14.1, %.loc28_14.2 [template = constants.%empty_tuple]
-// CHECK:STDOUT:   assign file.%A.var.loc28, %.loc28_15
+// CHECK:STDOUT:   %.loc29_14.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:   %.loc29_14.2: init %empty_tuple.type = tuple_init () to file.%A.var.loc29 [template = constants.%empty_tuple]
+// CHECK:STDOUT:   %.loc29_15: init %empty_tuple.type = converted %.loc29_14.1, %.loc29_14.2 [template = constants.%empty_tuple]
+// CHECK:STDOUT:   assign file.%A.var.loc29, %.loc29_15
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/var/no_prelude/import_access.carbon b/toolchain/check/testdata/var/no_prelude/import_access.carbon
index e8aa4dc69cdc..b7edd98572d1 100644
--- a/toolchain/check/testdata/var/no_prelude/import_access.carbon
+++ b/toolchain/check/testdata/var/no_prelude/import_access.carbon
@@ -46,9 +46,10 @@ package Other library "[[@TEST_NAME]]";
 
 import Test library "def";
 
-// CHECK:STDERR: fail_other_def.carbon:[[@LINE+3]]:14: error: member name `v` not found in `Test` [MemberNameNotFoundInScope]
+// CHECK:STDERR: fail_other_def.carbon:[[@LINE+4]]:14: error: member name `v` not found in `Test` [MemberNameNotFoundInScope]
 // CHECK:STDERR: var v2: () = Test.v;
 // CHECK:STDERR:              ^~~~~~
+// CHECK:STDERR:
 var v2: () = Test.v;
 
 // CHECK:STDOUT: --- def.carbon
diff --git a/toolchain/check/testdata/where_expr/constraints.carbon b/toolchain/check/testdata/where_expr/constraints.carbon
index b311cce26d2a..a35a48c0bf0c 100644
--- a/toolchain/check/testdata/where_expr/constraints.carbon
+++ b/toolchain/check/testdata/where_expr/constraints.carbon
@@ -104,15 +104,16 @@ fn EmptyStruct(Y:! J where .Self == {});
 
 // TODO: Should report that `C` does not meeet the constraint.
 fn NotEmptyStruct() {
-  // CHECK:STDERR: fail_todo_enforce_constraint.carbon:[[@LINE+9]]:3: error: cannot implicitly convert from `type` to `J where...` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_todo_enforce_constraint.carbon:[[@LINE+10]]:3: error: cannot implicitly convert from `type` to `J where...` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   EmptyStruct(C);
   // CHECK:STDERR:   ^~~~~~~~~~~~~~
-  // CHECK:STDERR: fail_todo_enforce_constraint.carbon:[[@LINE+6]]:3: note: type `type` does not implement interface `Core.ImplicitAs(J where...)` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR: fail_todo_enforce_constraint.carbon:[[@LINE+7]]:3: note: type `type` does not implement interface `Core.ImplicitAs(J where...)` [MissingImplInMemberAccessNote]
   // CHECK:STDERR:   EmptyStruct(C);
   // CHECK:STDERR:   ^~~~~~~~~~~~~~
   // CHECK:STDERR: fail_todo_enforce_constraint.carbon:[[@LINE-10]]:1: note: while deducing parameters of generic declared here [DeductionGenericHere]
   // CHECK:STDERR: fn EmptyStruct(Y:! J where .Self == {});
   // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  // CHECK:STDERR:
   EmptyStruct(C);
 }
 
@@ -679,7 +680,7 @@ fn NotEmptyStruct() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %EmptyStruct.ref: %EmptyStruct.type = name_ref EmptyStruct, file.%EmptyStruct.decl [template = constants.%EmptyStruct]
 // CHECK:STDOUT:   %C.ref: type = name_ref C, file.%C.decl [template = constants.%C]
-// CHECK:STDOUT:   %.loc39: %J_where.type = converted %C.ref, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc40: %J_where.type = converted %C.ref, <error> [template = <error>]
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/where_expr/designator.carbon b/toolchain/check/testdata/where_expr/designator.carbon
index dd2759e1a3e1..1b99b314f490 100644
--- a/toolchain/check/testdata/where_expr/designator.carbon
+++ b/toolchain/check/testdata/where_expr/designator.carbon
@@ -80,9 +80,10 @@ class C {
 library "[[@TEST_NAME]]";
 
 class D {
-  // CHECK:STDERR: fail_dot_self_method_return_type.carbon:[[@LINE+3]]:13: error: name `.Self` not found [NameNotFound]
+  // CHECK:STDERR: fail_dot_self_method_return_type.carbon:[[@LINE+4]]:13: error: name `.Self` not found [NameNotFound]
   // CHECK:STDERR:   fn G() -> .Self { return Self; }
   // CHECK:STDERR:             ^~~~~
+  // CHECK:STDERR:
   fn G() -> .Self { return Self; }
 }
 
diff --git a/toolchain/check/testdata/where_expr/equal_rewrite.carbon b/toolchain/check/testdata/where_expr/equal_rewrite.carbon
index 60dd85d1c283..83d3e26d3ced 100644
--- a/toolchain/check/testdata/where_expr/equal_rewrite.carbon
+++ b/toolchain/check/testdata/where_expr/equal_rewrite.carbon
@@ -210,12 +210,13 @@ let H: (E where .F = bool and .G = ()) = f64;
 // CHECK:STDERR:
 let J: ((E where .F = {}) where .G = i32) = bool;
 
-// CHECK:STDERR: fail_type_does_not_implement_where.carbon:[[@LINE+6]]:1: error: cannot implicitly convert from `type` to `E where .(E.F) = .(E.G)` [ImplicitAsConversionFailure]
+// CHECK:STDERR: fail_type_does_not_implement_where.carbon:[[@LINE+7]]:1: error: cannot implicitly convert from `type` to `E where .(E.F) = .(E.G)` [ImplicitAsConversionFailure]
 // CHECK:STDERR: let K: (E where .F = .Self.G) = bool;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_type_does_not_implement_where.carbon:[[@LINE+3]]:1: note: type `type` does not implement interface `Core.ImplicitAs(E where .(E.F) = .(E.G))` [MissingImplInMemberAccessNote]
+// CHECK:STDERR: fail_type_does_not_implement_where.carbon:[[@LINE+4]]:1: note: type `type` does not implement interface `Core.ImplicitAs(E where .(E.F) = .(E.G))` [MissingImplInMemberAccessNote]
 // CHECK:STDERR: let K: (E where .F = .Self.G) = bool;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
 let K: (E where .F = .Self.G) = bool;
 
 // CHECK:STDOUT: --- equal_constraint.carbon
@@ -1381,8 +1382,8 @@ let K: (E where .F = .Self.G) = bool;
 // CHECK:STDOUT:   %bool.make_type.loc27: init type = call constants.%Bool() [template = bool]
 // CHECK:STDOUT:   %.loc27: %E_where.type.bef = converted %bool.make_type.loc27, <error> [template = <error>]
 // CHECK:STDOUT:   %J: %E_where.type.bef = bind_name J, <error>
-// CHECK:STDOUT:   %bool.make_type.loc35: init type = call constants.%Bool() [template = bool]
-// CHECK:STDOUT:   %.loc35: %E_where.type.503 = converted %bool.make_type.loc35, <error> [template = <error>]
+// CHECK:STDOUT:   %bool.make_type.loc36: init type = call constants.%Bool() [template = bool]
+// CHECK:STDOUT:   %.loc36: %E_where.type.503 = converted %bool.make_type.loc36, <error> [template = <error>]
 // CHECK:STDOUT:   %K: %E_where.type.503 = bind_name K, <error>
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/where_expr/fail_not_facet.carbon b/toolchain/check/testdata/where_expr/fail_not_facet.carbon
index 5aba4094ff11..7352eda2e23c 100644
--- a/toolchain/check/testdata/where_expr/fail_not_facet.carbon
+++ b/toolchain/check/testdata/where_expr/fail_not_facet.carbon
@@ -32,9 +32,10 @@ fn G(U:! NOT_DECLARED where .Self == bool);
 
 library "[[@TEST_NAME]]";
 
-// CHECK:STDERR: fail_var.carbon:[[@LINE+3]]:8: error: name `e` not found [NameNotFound]
+// CHECK:STDERR: fail_var.carbon:[[@LINE+4]]:8: error: name `e` not found [NameNotFound]
 // CHECK:STDERR: var v: e where .x = 3;
 // CHECK:STDERR:        ^
+// CHECK:STDERR:
 var v: e where .x = 3;
 
 // CHECK:STDOUT: --- fail_left_where_not_facet.carbon
diff --git a/toolchain/check/testdata/while/fail_bad_condition.carbon b/toolchain/check/testdata/while/fail_bad_condition.carbon
index f76c9cd5621d..9c3d80cbf424 100644
--- a/toolchain/check/testdata/while/fail_bad_condition.carbon
+++ b/toolchain/check/testdata/while/fail_bad_condition.carbon
@@ -9,12 +9,13 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/while/fail_bad_condition.carbon
 
 fn While() {
-  // CHECK:STDERR: fail_bad_condition.carbon:[[@LINE+6]]:9: error: cannot implicitly convert from `String` to `bool` [ImplicitAsConversionFailure]
+  // CHECK:STDERR: fail_bad_condition.carbon:[[@LINE+7]]:9: error: cannot implicitly convert from `String` to `bool` [ImplicitAsConversionFailure]
   // CHECK:STDERR:   while ("Hello") {}
   // CHECK:STDERR:         ^~~~~~~~~
-  // CHECK:STDERR: fail_bad_condition.carbon:[[@LINE+3]]:9: note: type `String` does not implement interface `Core.ImplicitAs(bool)` [MissingImplInMemberAccessNote]
+  // CHECK:STDERR: fail_bad_condition.carbon:[[@LINE+4]]:9: note: type `String` does not implement interface `Core.ImplicitAs(bool)` [MissingImplInMemberAccessNote]
   // CHECK:STDERR:   while ("Hello") {}
   // CHECK:STDERR:         ^~~~~~~~~
+  // CHECK:STDERR:
   while ("Hello") {}
 }
 
@@ -49,7 +50,7 @@ fn While() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !while.cond:
 // CHECK:STDOUT:   %str: String = string_literal "Hello" [template = constants.%str]
-// CHECK:STDOUT:   %.loc18: bool = converted %str, <error> [template = <error>]
+// CHECK:STDOUT:   %.loc19: bool = converted %str, <error> [template = <error>]
 // CHECK:STDOUT:   if <error> br !while.body else br !while.done
 // CHECK:STDOUT:
 // CHECK:STDOUT: !while.body:
diff --git a/toolchain/check/testdata/while/fail_break_continue.carbon b/toolchain/check/testdata/while/fail_break_continue.carbon
index afc6b6f36f2b..dbc4891c90e2 100644
--- a/toolchain/check/testdata/while/fail_break_continue.carbon
+++ b/toolchain/check/testdata/while/fail_break_continue.carbon
@@ -28,9 +28,10 @@ fn While() {
   // CHECK:STDERR:   ^~~~~~~~
   // CHECK:STDERR:
   continue;
-  // CHECK:STDERR: fail_break_continue.carbon:[[@LINE+3]]:3: error: `break` can only be used in a loop [BreakOutsideLoop]
+  // CHECK:STDERR: fail_break_continue.carbon:[[@LINE+4]]:3: error: `break` can only be used in a loop [BreakOutsideLoop]
   // CHECK:STDERR:   break;
   // CHECK:STDERR:   ^~~~~
+  // CHECK:STDERR:
   break;
 }
 
diff --git a/toolchain/codegen/testdata/fail_target_triple.carbon b/toolchain/codegen/testdata/fail_target_triple.carbon
index dcceae7684a4..8a24666c74b4 100644
--- a/toolchain/codegen/testdata/fail_target_triple.carbon
+++ b/toolchain/codegen/testdata/fail_target_triple.carbon
@@ -10,5 +10,6 @@
 //   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/codegen/testdata/fail_target_triple.carbon
 // NOAUTOUPDATE
 // CHECK:STDERR: error: invalid target: {{.*}}x86_687{{.*}}
+// CHECK:STDERR:
 
 fn Main() {}
diff --git a/toolchain/diagnostics/testdata/fail_multiline_token.carbon b/toolchain/diagnostics/testdata/fail_multiline_token.carbon
index 75ae95b0983f..2c759d421b91 100644
--- a/toolchain/diagnostics/testdata/fail_multiline_token.carbon
+++ b/toolchain/diagnostics/testdata/fail_multiline_token.carbon
@@ -10,9 +10,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/diagnostics/testdata/fail_multiline_token.carbon
 
-// CHECK:STDERR: fail_multiline_token.carbon:[[@LINE+3]]:1: error: unrecognized declaration introducer
+// CHECK:STDERR: fail_multiline_token.carbon:[[@LINE+4]]:1: error: unrecognized declaration introducer
 // CHECK:STDERR: '''
 // CHECK:STDERR: ^~~
+// CHECK:STDERR:
 '''
 hello
 '''
diff --git a/toolchain/driver/testdata/fail_errors_in_two_files.carbon b/toolchain/driver/testdata/fail_errors_in_two_files.carbon
index 7b4f0ad14f4a..a23d52cd18f9 100644
--- a/toolchain/driver/testdata/fail_errors_in_two_files.carbon
+++ b/toolchain/driver/testdata/fail_errors_in_two_files.carbon
@@ -21,7 +21,8 @@ fn run(String program) {
 
 // --- fail_file2.carbon
 
-// CHECK:STDERR: fail_file2.carbon:[[@LINE+3]]:10: error: invalid digit 'a' in decimal numeric literal
+// CHECK:STDERR: fail_file2.carbon:[[@LINE+4]]:10: error: invalid digit 'a' in decimal numeric literal
 // CHECK:STDERR: var x = 3a;
 // CHECK:STDERR:          ^
+// CHECK:STDERR:
 var x = 3a;
diff --git a/toolchain/driver/testdata/fail_errors_sorted.carbon b/toolchain/driver/testdata/fail_errors_sorted.carbon
index 4b5da0d0efde..a4514661806a 100644
--- a/toolchain/driver/testdata/fail_errors_sorted.carbon
+++ b/toolchain/driver/testdata/fail_errors_sorted.carbon
@@ -17,7 +17,8 @@
 fn run(String program) {
   return True;
 
-// CHECK:STDERR: fail_errors_sorted.carbon:[[@LINE+3]]:10: error: invalid digit 'a' in decimal numeric literal
+// CHECK:STDERR: fail_errors_sorted.carbon:[[@LINE+4]]:10: error: invalid digit 'a' in decimal numeric literal
 // CHECK:STDERR: var x = 3a;
 // CHECK:STDERR:          ^
+// CHECK:STDERR:
 var x = 3a;
diff --git a/toolchain/driver/testdata/fail_errors_streamed.carbon b/toolchain/driver/testdata/fail_errors_streamed.carbon
index 0a842c256d43..789edd7a2f7f 100644
--- a/toolchain/driver/testdata/fail_errors_streamed.carbon
+++ b/toolchain/driver/testdata/fail_errors_streamed.carbon
@@ -13,11 +13,12 @@
 fn run(String program) {
   return True;
 
-// CHECK:STDERR: fail_errors_streamed.carbon:[[@LINE+7]]:10: error: invalid digit 'a' in decimal numeric literal
+// CHECK:STDERR: fail_errors_streamed.carbon:[[@LINE+8]]:10: error: invalid digit 'a' in decimal numeric literal
 // CHECK:STDERR: var x = 3a;
 // CHECK:STDERR:          ^
 // CHECK:STDERR:
 // CHECK:STDERR: fail_errors_streamed.carbon:[[@LINE-7]]:24: error: opening symbol without a corresponding closing symbol
 // CHECK:STDERR: fn run(String program) {
 // CHECK:STDERR:                        ^
+// CHECK:STDERR:
 var x = 3a;
diff --git a/toolchain/driver/testdata/fail_flag.carbon b/toolchain/driver/testdata/fail_flag.carbon
index 75e0a07d33ea..7fb726990647 100644
--- a/toolchain/driver/testdata/fail_flag.carbon
+++ b/toolchain/driver/testdata/fail_flag.carbon
@@ -10,3 +10,4 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/driver/testdata/fail_flag.carbon
 // CHECK:STDERR: error: unknown option `--non-existent-flag`
+// CHECK:STDERR:
diff --git a/toolchain/driver/testdata/fail_flush_errors.carbon b/toolchain/driver/testdata/fail_flush_errors.carbon
index df34d16feb9e..3f9ad2ff65da 100644
--- a/toolchain/driver/testdata/fail_flush_errors.carbon
+++ b/toolchain/driver/testdata/fail_flush_errors.carbon
@@ -31,8 +31,9 @@ fn F() {
 
   // Add the name into the string table via a declaration rather than an expression.
   if (true) { var undeclared3: () = (); }
-  // CHECK:STDERR: fail_flush_errors.carbon:[[@LINE+3]]:3: error: name `undeclared3` not found
+  // CHECK:STDERR: fail_flush_errors.carbon:[[@LINE+4]]:3: error: name `undeclared3` not found
   // CHECK:STDERR:   undeclared3;
   // CHECK:STDERR:   ^~~~~~~~~~~
+  // CHECK:STDERR:
   undeclared3;
 }
diff --git a/toolchain/driver/testdata/fail_input_is_directory.carbon b/toolchain/driver/testdata/fail_input_is_directory.carbon
index 725e27bd5f4a..2b9411de59db 100644
--- a/toolchain/driver/testdata/fail_input_is_directory.carbon
+++ b/toolchain/driver/testdata/fail_input_is_directory.carbon
@@ -10,3 +10,4 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/driver/testdata/fail_input_is_directory.carbon
 // CHECK:STDERR: .: error: error opening file for read: Invalid argument
+// CHECK:STDERR:
diff --git a/toolchain/driver/testdata/fail_missing_file.carbon b/toolchain/driver/testdata/fail_missing_file.carbon
index 4dcb817a6fb3..64891b558ee2 100644
--- a/toolchain/driver/testdata/fail_missing_file.carbon
+++ b/toolchain/driver/testdata/fail_missing_file.carbon
@@ -10,3 +10,4 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/driver/testdata/fail_missing_file.carbon
 // CHECK:STDERR: not_file.carbon: error: error opening file for read: No such file or directory [ErrorOpeningFile]
+// CHECK:STDERR:
diff --git a/toolchain/driver/testdata/fail_missing_stdin_output.carbon b/toolchain/driver/testdata/fail_missing_stdin_output.carbon
index a29d3c0e362b..0be0fcdeb2e4 100644
--- a/toolchain/driver/testdata/fail_missing_stdin_output.carbon
+++ b/toolchain/driver/testdata/fail_missing_stdin_output.carbon
@@ -10,3 +10,4 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/driver/testdata/fail_missing_stdin_output.carbon
 // CHECK:STDERR: error: output file name must be specified for input `-` that is not a regular file
+// CHECK:STDERR:
diff --git a/toolchain/format/testdata/basics/fail_invalid_comment.carbon b/toolchain/format/testdata/basics/fail_invalid_comment.carbon
index eecb8e2b10e4..3e38551e778f 100644
--- a/toolchain/format/testdata/basics/fail_invalid_comment.carbon
+++ b/toolchain/format/testdata/basics/fail_invalid_comment.carbon
@@ -17,6 +17,7 @@
 // CHECK:STDERR: fail_test.carbon:2:3: error: whitespace is required after '//'
 // CHECK:STDERR: //f
 // CHECK:STDERR:   ^
+// CHECK:STDERR:
 // CHECK:STDOUT:
 // CHECK:STDOUT: //f
 // CHECK:STDOUT:
diff --git a/toolchain/format/testdata/basics/fail_nonexistent.carbon b/toolchain/format/testdata/basics/fail_nonexistent.carbon
index 0285786412eb..cc274933d14b 100644
--- a/toolchain/format/testdata/basics/fail_nonexistent.carbon
+++ b/toolchain/format/testdata/basics/fail_nonexistent.carbon
@@ -9,3 +9,4 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/format/testdata/basics/fail_nonexistent.carbon
 // CHECK:STDERR: fail_target_file.carbon: error: error opening file for read: No such file or directory
+// CHECK:STDERR:
diff --git a/toolchain/lex/testdata/fail_bad_comment_introducers.carbon b/toolchain/lex/testdata/fail_bad_comment_introducers.carbon
index d08be7075680..a714af73646d 100644
--- a/toolchain/lex/testdata/fail_bad_comment_introducers.carbon
+++ b/toolchain/lex/testdata/fail_bad_comment_introducers.carbon
@@ -45,9 +45,10 @@
 // As we have specialized code to scan short indented comment blocks, make sure
 // the behavior is preserved even for (absurdly) large indents.
 
-                                                                                // CHECK:STDERR: fail_bad_comment_introducers.carbon:[[@LINE+3]]:83: error: whitespace is required after '//' [NoWhitespaceAfterCommentIntroducer]
+                                                                                // CHECK:STDERR: fail_bad_comment_introducers.carbon:[[@LINE+4]]:83: error: whitespace is required after '//' [NoWhitespaceAfterCommentIntroducer]
                                                                                 // CHECK:STDERR:                                                                                 //very indented block
                                                                                 // CHECK:STDERR:                                                                                   ^
+                                                                                // CHECK:STDERR:
                                                                                 //very indented block
                                                                                 //very indented block
                                                                                 //very indented block
diff --git a/toolchain/lex/testdata/fail_bad_comment_introducers_mid_block_indent_change.carbon b/toolchain/lex/testdata/fail_bad_comment_introducers_mid_block_indent_change.carbon
index bc472077fad1..2204bdf177ca 100644
--- a/toolchain/lex/testdata/fail_bad_comment_introducers_mid_block_indent_change.carbon
+++ b/toolchain/lex/testdata/fail_bad_comment_introducers_mid_block_indent_change.carbon
@@ -34,6 +34,7 @@
 // CHECK:STDERR: fail_bad_comment_introducers_mid_block_indent_change.carbon:[[@LINE-19]]:3: error: whitespace is required after '//' [NoWhitespaceAfterCommentIntroducer]
 // CHECK:STDERR: //abc
 // CHECK:STDERR:   ^
+// CHECK:STDERR:
 
 // CHECK:STDOUT: - filename: fail_bad_comment_introducers_mid_block_indent_change.carbon
 // CHECK:STDOUT:   tokens:
diff --git a/toolchain/lex/testdata/fail_bad_raw_identifier.carbon b/toolchain/lex/testdata/fail_bad_raw_identifier.carbon
index 3e2ee2a25e58..f7d9bf7d433b 100644
--- a/toolchain/lex/testdata/fail_bad_raw_identifier.carbon
+++ b/toolchain/lex/testdata/fail_bad_raw_identifier.carbon
@@ -91,9 +91,10 @@ r#"hello"#
 // CHECK:STDOUT:   tokens:
 
 // Ensure that we correctly handle a `#` as the first token in the file.
-// CHECK:STDERR: fail_hash_at_start_of_file.carbon:[[@LINE+3]]:1: error: encountered unrecognized characters while parsing [UnrecognizedCharacters]
+// CHECK:STDERR: fail_hash_at_start_of_file.carbon:[[@LINE+4]]:1: error: encountered unrecognized characters while parsing [UnrecognizedCharacters]
 // CHECK:STDERR: #foo
 // CHECK:STDERR: ^
+// CHECK:STDERR:
 #foo
 // CHECK:STDOUT:   - { index: 1, kind:      'Error', line: {{ *}}[[@LINE-1]], column:   1, indent: 1, spelling: '#', has_leading_space: true }
 // CHECK:STDOUT:   - { index: 2, kind: 'Identifier', line: {{ *}}[[@LINE-2]], column:   2, indent: 1, spelling: 'foo', identifier: 0 }
diff --git a/toolchain/lex/testdata/fail_block_string_second_line.carbon b/toolchain/lex/testdata/fail_block_string_second_line.carbon
index 9b4178dad474..9b4769dc8359 100644
--- a/toolchain/lex/testdata/fail_block_string_second_line.carbon
+++ b/toolchain/lex/testdata/fail_block_string_second_line.carbon
@@ -16,12 +16,13 @@ var s: String = '''
 // CHECK:STDERR: fail_block_string_second_line.carbon:[[@LINE-10]]:3: error: only whitespace is permitted before the closing `'''` of a multi-line string [ContentBeforeStringTerminator]
 // CHECK:STDERR:   error here: '''
 // CHECK:STDERR:   ^
+// CHECK:STDERR:
 // CHECK:STDOUT: - filename: fail_block_string_second_line.carbon
 // CHECK:STDOUT:   tokens:
-// CHECK:STDOUT:   - { index: 1, kind:               'Var', line: {{ *}}[[@LINE-16]], column:  1, indent: 1, spelling: 'var', has_leading_space: true }
-// CHECK:STDOUT:   - { index: 2, kind:        'Identifier', line: {{ *}}[[@LINE-17]], column:  5, indent: 1, spelling: 's', identifier: 0, has_leading_space: true }
-// CHECK:STDOUT:   - { index: 3, kind:             'Colon', line: {{ *}}[[@LINE-18]], column:  6, indent: 1, spelling: ':' }
-// CHECK:STDOUT:   - { index: 4, kind: 'StringTypeLiteral', line: {{ *}}[[@LINE-19]], column:  8, indent: 1, spelling: 'String', has_leading_space: true }
-// CHECK:STDOUT:   - { index: 5, kind:             'Equal', line: {{ *}}[[@LINE-20]], column: 15, indent: 1, spelling: '=', has_leading_space: true }
-// CHECK:STDOUT:   - { index: 6, kind:     'StringLiteral', line: {{ *}}[[@LINE-21]], column: 17, indent: 1, spelling: ''''
+// CHECK:STDOUT:   - { index: 1, kind:               'Var', line: {{ *}}[[@LINE-17]], column:  1, indent: 1, spelling: 'var', has_leading_space: true }
+// CHECK:STDOUT:   - { index: 2, kind:        'Identifier', line: {{ *}}[[@LINE-18]], column:  5, indent: 1, spelling: 's', identifier: 0, has_leading_space: true }
+// CHECK:STDOUT:   - { index: 3, kind:             'Colon', line: {{ *}}[[@LINE-19]], column:  6, indent: 1, spelling: ':' }
+// CHECK:STDOUT:   - { index: 4, kind: 'StringTypeLiteral', line: {{ *}}[[@LINE-20]], column:  8, indent: 1, spelling: 'String', has_leading_space: true }
+// CHECK:STDOUT:   - { index: 5, kind:             'Equal', line: {{ *}}[[@LINE-21]], column: 15, indent: 1, spelling: '=', has_leading_space: true }
+// CHECK:STDOUT:   - { index: 6, kind:     'StringLiteral', line: {{ *}}[[@LINE-22]], column: 17, indent: 1, spelling: ''''
 // CHECK:STDOUT:   error here: '''', value: `error here: `, has_leading_space: true }
diff --git a/toolchain/lex/testdata/fail_mismatched_brackets.carbon b/toolchain/lex/testdata/fail_mismatched_brackets.carbon
index f2ab84db8113..5c18af52a42f 100644
--- a/toolchain/lex/testdata/fail_mismatched_brackets.carbon
+++ b/toolchain/lex/testdata/fail_mismatched_brackets.carbon
@@ -26,8 +26,9 @@
 // CHECK:STDOUT:   - { index: 3, kind:      'Error', line: {{ *}}[[@LINE-2]], column:   3, indent: 1, spelling: '}', has_leading_space: true }
 // CHECK:STDOUT:   - { index: 4, kind: 'CloseParen', line: {{ *}}[[@LINE-3]], column:   5, indent: 1, spelling: ')', opening_token: 2, has_leading_space: true }
 
-// CHECK:STDERR: fail_mismatched_brackets.carbon:[[@LINE+3]]:1: error: opening symbol without a corresponding closing symbol [UnmatchedOpening]
+// CHECK:STDERR: fail_mismatched_brackets.carbon:[[@LINE+4]]:1: error: opening symbol without a corresponding closing symbol [UnmatchedOpening]
 // CHECK:STDERR: [
 // CHECK:STDERR: ^
+// CHECK:STDERR:
 [
 // CHECK:STDOUT:   - { index: 5, kind:      'Error', line: {{ *}}[[@LINE-1]], column:   1, indent: 1, spelling: '[', has_leading_space: true }
diff --git a/toolchain/lex/testdata/fail_mismatched_brackets_2.carbon b/toolchain/lex/testdata/fail_mismatched_brackets_2.carbon
index af574bdaab9a..96de56381e72 100644
--- a/toolchain/lex/testdata/fail_mismatched_brackets_2.carbon
+++ b/toolchain/lex/testdata/fail_mismatched_brackets_2.carbon
@@ -21,18 +21,19 @@ fn F() {
 // CHECK:STDERR: fail_mismatched_brackets_2.carbon:[[@LINE-9]]:1: error: closing symbol without a corresponding opening symbol [UnmatchedClosing]
 // CHECK:STDERR: }
 // CHECK:STDERR: ^
+// CHECK:STDERR:
 // CHECK:STDOUT: - filename: fail_mismatched_brackets_2.carbon
 // CHECK:STDOUT:   tokens:
-// CHECK:STDOUT:   - { index:  1, kind:              'Fn', line: {{ *}}[[@LINE-18]], column:   1, indent: 1, spelling: 'fn', has_leading_space: true }
-// CHECK:STDOUT:   - { index:  2, kind:      'Identifier', line: {{ *}}[[@LINE-19]], column:   4, indent: 1, spelling: 'F', identifier: 0, has_leading_space: true }
-// CHECK:STDOUT:   - { index:  3, kind:       'OpenParen', line: {{ *}}[[@LINE-20]], column:   5, indent: 1, spelling: '(', closing_token: 4 }
-// CHECK:STDOUT:   - { index:  4, kind:      'CloseParen', line: {{ *}}[[@LINE-21]], column:   6, indent: 1, spelling: ')', opening_token: 3 }
-// CHECK:STDOUT:   - { index:  5, kind:  'OpenCurlyBrace', line: {{ *}}[[@LINE-22]], column:   8, indent: 1, spelling: '{', closing_token: 12, has_leading_space: true }
-// CHECK:STDOUT:   - { index:  6, kind:              'If', line: {{ *}}[[@LINE-22]], column:   3, indent: 3, spelling: 'if', has_leading_space: true }
-// CHECK:STDOUT:   - { index:  7, kind:       'OpenParen', line: {{ *}}[[@LINE-23]], column:   6, indent: 3, spelling: '(', closing_token: 9, has_leading_space: true }
-// CHECK:STDOUT:   - { index:  8, kind:      'Identifier', line: {{ *}}[[@LINE-24]], column:   7, indent: 3, spelling: 'thing1', identifier: 1 }
-// CHECK:STDOUT:   - { index:  9, kind:      'CloseParen', line: {{ *}}[[@LINE-25]], column:  13, indent: 3, spelling: ')', opening_token: 7 }
-// CHECK:STDOUT:   - { index: 10, kind:      'Identifier', line: {{ *}}[[@LINE-25]], column:   5, indent: 5, spelling: 'thing2', identifier: 2, has_leading_space: true }
-// CHECK:STDOUT:   - { index: 11, kind:            'Semi', line: {{ *}}[[@LINE-26]], column:  11, indent: 5, spelling: ';' }
-// CHECK:STDOUT:   - { index: 12, kind: 'CloseCurlyBrace', line: {{ *}}[[@LINE-26]], column:   3, indent: 3, spelling: '}', opening_token: 5, has_leading_space: true }
-// CHECK:STDOUT:   - { index: 13, kind:           'Error', line: {{ *}}[[@LINE-26]], column:   1, indent: 1, spelling: '}', has_leading_space: true }
+// CHECK:STDOUT:   - { index:  1, kind:              'Fn', line: {{ *}}[[@LINE-19]], column:   1, indent: 1, spelling: 'fn', has_leading_space: true }
+// CHECK:STDOUT:   - { index:  2, kind:      'Identifier', line: {{ *}}[[@LINE-20]], column:   4, indent: 1, spelling: 'F', identifier: 0, has_leading_space: true }
+// CHECK:STDOUT:   - { index:  3, kind:       'OpenParen', line: {{ *}}[[@LINE-21]], column:   5, indent: 1, spelling: '(', closing_token: 4 }
+// CHECK:STDOUT:   - { index:  4, kind:      'CloseParen', line: {{ *}}[[@LINE-22]], column:   6, indent: 1, spelling: ')', opening_token: 3 }
+// CHECK:STDOUT:   - { index:  5, kind:  'OpenCurlyBrace', line: {{ *}}[[@LINE-23]], column:   8, indent: 1, spelling: '{', closing_token: 12, has_leading_space: true }
+// CHECK:STDOUT:   - { index:  6, kind:              'If', line: {{ *}}[[@LINE-23]], column:   3, indent: 3, spelling: 'if', has_leading_space: true }
+// CHECK:STDOUT:   - { index:  7, kind:       'OpenParen', line: {{ *}}[[@LINE-24]], column:   6, indent: 3, spelling: '(', closing_token: 9, has_leading_space: true }
+// CHECK:STDOUT:   - { index:  8, kind:      'Identifier', line: {{ *}}[[@LINE-25]], column:   7, indent: 3, spelling: 'thing1', identifier: 1 }
+// CHECK:STDOUT:   - { index:  9, kind:      'CloseParen', line: {{ *}}[[@LINE-26]], column:  13, indent: 3, spelling: ')', opening_token: 7 }
+// CHECK:STDOUT:   - { index: 10, kind:      'Identifier', line: {{ *}}[[@LINE-26]], column:   5, indent: 5, spelling: 'thing2', identifier: 2, has_leading_space: true }
+// CHECK:STDOUT:   - { index: 11, kind:            'Semi', line: {{ *}}[[@LINE-27]], column:  11, indent: 5, spelling: ';' }
+// CHECK:STDOUT:   - { index: 12, kind: 'CloseCurlyBrace', line: {{ *}}[[@LINE-27]], column:   3, indent: 3, spelling: '}', opening_token: 5, has_leading_space: true }
+// CHECK:STDOUT:   - { index: 13, kind:           'Error', line: {{ *}}[[@LINE-27]], column:   1, indent: 1, spelling: '}', has_leading_space: true }
diff --git a/toolchain/lex/testdata/fail_multifile.carbon b/toolchain/lex/testdata/fail_multifile.carbon
index 58b26f3719b9..f145d717c7f0 100644
--- a/toolchain/lex/testdata/fail_multifile.carbon
+++ b/toolchain/lex/testdata/fail_multifile.carbon
@@ -21,8 +21,9 @@
 // --- fail_b.carbon
 // CHECK:STDOUT: - filename: fail_b.carbon
 // CHECK:STDOUT:   tokens:
-// CHECK:STDERR: fail_b.carbon:[[@LINE+3]]:3: error: empty digit sequence in numeric literal [EmptyDigitSequence]
+// CHECK:STDERR: fail_b.carbon:[[@LINE+4]]:3: error: empty digit sequence in numeric literal [EmptyDigitSequence]
 // CHECK:STDERR: 2.b
 // CHECK:STDERR:   ^
+// CHECK:STDERR:
 2.b
 // CHECK:STDOUT:   - { index: 1, kind:     'Error', line: {{ *}}[[@LINE-1]], column:   1, indent: 1, spelling: '2.b', has_leading_space: true }
diff --git a/toolchain/lex/testdata/fail_trailing_comments.carbon b/toolchain/lex/testdata/fail_trailing_comments.carbon
index 2ca924cae03c..b879925b8e06 100644
--- a/toolchain/lex/testdata/fail_trailing_comments.carbon
+++ b/toolchain/lex/testdata/fail_trailing_comments.carbon
@@ -27,26 +27,27 @@ var c: i32 = 0.4; // still more trailing comment
 // CHECK:STDERR: fail_trailing_comments.carbon:[[@LINE-17]]:19: error: trailing comments are not permitted [TrailingComment]
 // CHECK:STDERR: var c: i32 = 0.4; // still more trailing comment
 // CHECK:STDERR:                   ^
+// CHECK:STDERR:
 // CHECK:STDOUT: - filename: fail_trailing_comments.carbon
 // CHECK:STDOUT:   tokens:
-// CHECK:STDOUT:   - { index:  1, kind:            'Var', line: {{ *}}[[@LINE-24]], column:   1, indent: 1, spelling: 'var', has_leading_space: true }
-// CHECK:STDOUT:   - { index:  2, kind:     'Identifier', line: {{ *}}[[@LINE-25]], column:   5, indent: 1, spelling: 'a', identifier: 0, has_leading_space: true }
-// CHECK:STDOUT:   - { index:  3, kind:          'Colon', line: {{ *}}[[@LINE-26]], column:   6, indent: 1, spelling: ':' }
-// CHECK:STDOUT:   - { index:  4, kind: 'IntTypeLiteral', line: {{ *}}[[@LINE-27]], column:   8, indent: 1, spelling: 'i32', has_leading_space: true }
-// CHECK:STDOUT:   - { index:  5, kind:          'Equal', line: {{ *}}[[@LINE-28]], column:  12, indent: 1, spelling: '=', has_leading_space: true }
-// CHECK:STDOUT:   - { index:  6, kind:     'IntLiteral', line: {{ *}}[[@LINE-29]], column:  14, indent: 1, spelling: '1', value: `1`, has_leading_space: true }
-// CHECK:STDOUT:   - { index:  7, kind:           'Semi', line: {{ *}}[[@LINE-30]], column:  15, indent: 1, spelling: ';' }
-// CHECK:STDOUT:   - { index:  8, kind:            'Var', line: {{ *}}[[@LINE-30]], column:   1, indent: 1, spelling: 'var', has_leading_space: true }
-// CHECK:STDOUT:   - { index:  9, kind:     'Identifier', line: {{ *}}[[@LINE-31]], column:   5, indent: 1, spelling: 'b', identifier: 1, has_leading_space: true }
-// CHECK:STDOUT:   - { index: 10, kind:          'Colon', line: {{ *}}[[@LINE-32]], column:   6, indent: 1, spelling: ':' }
-// CHECK:STDOUT:   - { index: 11, kind:     'IntLiteral', line: {{ *}}[[@LINE-33]], column:   8, indent: 1, spelling: '32', value: `32`, has_leading_space: true }
-// CHECK:STDOUT:   - { index: 12, kind:          'Equal', line: {{ *}}[[@LINE-34]], column:  11, indent: 1, spelling: '=', has_leading_space: true }
-// CHECK:STDOUT:   - { index: 13, kind:     'IntLiteral', line: {{ *}}[[@LINE-35]], column:  13, indent: 1, spelling: '13', value: `13`, has_leading_space: true }
-// CHECK:STDOUT:   - { index: 14, kind:           'Semi', line: {{ *}}[[@LINE-36]], column:  15, indent: 1, spelling: ';' }
-// CHECK:STDOUT:   - { index: 15, kind:            'Var', line: {{ *}}[[@LINE-36]], column:   1, indent: 1, spelling: 'var', has_leading_space: true }
-// CHECK:STDOUT:   - { index: 16, kind:     'Identifier', line: {{ *}}[[@LINE-37]], column:   5, indent: 1, spelling: 'c', identifier: 2, has_leading_space: true }
-// CHECK:STDOUT:   - { index: 17, kind:          'Colon', line: {{ *}}[[@LINE-38]], column:   6, indent: 1, spelling: ':' }
-// CHECK:STDOUT:   - { index: 18, kind: 'IntTypeLiteral', line: {{ *}}[[@LINE-39]], column:   8, indent: 1, spelling: 'i32', has_leading_space: true }
-// CHECK:STDOUT:   - { index: 19, kind:          'Equal', line: {{ *}}[[@LINE-40]], column:  12, indent: 1, spelling: '=', has_leading_space: true }
-// CHECK:STDOUT:   - { index: 20, kind:    'RealLiteral', line: {{ *}}[[@LINE-41]], column:  14, indent: 1, spelling: '0.4', value: `4*10^-1`, has_leading_space: true }
-// CHECK:STDOUT:   - { index: 21, kind:           'Semi', line: {{ *}}[[@LINE-42]], column:  17, indent: 1, spelling: ';' }
+// CHECK:STDOUT:   - { index:  1, kind:            'Var', line: {{ *}}[[@LINE-25]], column:   1, indent: 1, spelling: 'var', has_leading_space: true }
+// CHECK:STDOUT:   - { index:  2, kind:     'Identifier', line: {{ *}}[[@LINE-26]], column:   5, indent: 1, spelling: 'a', identifier: 0, has_leading_space: true }
+// CHECK:STDOUT:   - { index:  3, kind:          'Colon', line: {{ *}}[[@LINE-27]], column:   6, indent: 1, spelling: ':' }
+// CHECK:STDOUT:   - { index:  4, kind: 'IntTypeLiteral', line: {{ *}}[[@LINE-28]], column:   8, indent: 1, spelling: 'i32', has_leading_space: true }
+// CHECK:STDOUT:   - { index:  5, kind:          'Equal', line: {{ *}}[[@LINE-29]], column:  12, indent: 1, spelling: '=', has_leading_space: true }
+// CHECK:STDOUT:   - { index:  6, kind:     'IntLiteral', line: {{ *}}[[@LINE-30]], column:  14, indent: 1, spelling: '1', value: `1`, has_leading_space: true }
+// CHECK:STDOUT:   - { index:  7, kind:           'Semi', line: {{ *}}[[@LINE-31]], column:  15, indent: 1, spelling: ';' }
+// CHECK:STDOUT:   - { index:  8, kind:            'Var', line: {{ *}}[[@LINE-31]], column:   1, indent: 1, spelling: 'var', has_leading_space: true }
+// CHECK:STDOUT:   - { index:  9, kind:     'Identifier', line: {{ *}}[[@LINE-32]], column:   5, indent: 1, spelling: 'b', identifier: 1, has_leading_space: true }
+// CHECK:STDOUT:   - { index: 10, kind:          'Colon', line: {{ *}}[[@LINE-33]], column:   6, indent: 1, spelling: ':' }
+// CHECK:STDOUT:   - { index: 11, kind:     'IntLiteral', line: {{ *}}[[@LINE-34]], column:   8, indent: 1, spelling: '32', value: `32`, has_leading_space: true }
+// CHECK:STDOUT:   - { index: 12, kind:          'Equal', line: {{ *}}[[@LINE-35]], column:  11, indent: 1, spelling: '=', has_leading_space: true }
+// CHECK:STDOUT:   - { index: 13, kind:     'IntLiteral', line: {{ *}}[[@LINE-36]], column:  13, indent: 1, spelling: '13', value: `13`, has_leading_space: true }
+// CHECK:STDOUT:   - { index: 14, kind:           'Semi', line: {{ *}}[[@LINE-37]], column:  15, indent: 1, spelling: ';' }
+// CHECK:STDOUT:   - { index: 15, kind:            'Var', line: {{ *}}[[@LINE-37]], column:   1, indent: 1, spelling: 'var', has_leading_space: true }
+// CHECK:STDOUT:   - { index: 16, kind:     'Identifier', line: {{ *}}[[@LINE-38]], column:   5, indent: 1, spelling: 'c', identifier: 2, has_leading_space: true }
+// CHECK:STDOUT:   - { index: 17, kind:          'Colon', line: {{ *}}[[@LINE-39]], column:   6, indent: 1, spelling: ':' }
+// CHECK:STDOUT:   - { index: 18, kind: 'IntTypeLiteral', line: {{ *}}[[@LINE-40]], column:   8, indent: 1, spelling: 'i32', has_leading_space: true }
+// CHECK:STDOUT:   - { index: 19, kind:          'Equal', line: {{ *}}[[@LINE-41]], column:  12, indent: 1, spelling: '=', has_leading_space: true }
+// CHECK:STDOUT:   - { index: 20, kind:    'RealLiteral', line: {{ *}}[[@LINE-42]], column:  14, indent: 1, spelling: '0.4', value: `4*10^-1`, has_leading_space: true }
+// CHECK:STDOUT:   - { index: 21, kind:           'Semi', line: {{ *}}[[@LINE-43]], column:  17, indent: 1, spelling: ';' }
diff --git a/toolchain/lex/testdata/multiline_string_literals.carbon b/toolchain/lex/testdata/multiline_string_literals.carbon
index 1c67d9fa098f..97760deb167e 100644
--- a/toolchain/lex/testdata/multiline_string_literals.carbon
+++ b/toolchain/lex/testdata/multiline_string_literals.carbon
@@ -32,6 +32,7 @@ a
 // CHECK:STDERR: fail_quotes.carbon:2:1: error: use `'''` delimiters for a multi-line string literal, not `"""` [MultiLineStringWithDoubleQuotes]
 // CHECK:STDERR: """
 // CHECK:STDERR: ^
+// CHECK:STDERR:
 // CHECK:STDOUT: - filename: fail_indent_mismatch.carbon
 // CHECK:STDOUT:   tokens:
 // CHECK:STDOUT:   - { index: 1, kind: 'StringLiteral', line: {{ *}}2, column: 3, indent: 3, spelling: ''''
diff --git a/toolchain/lex/testdata/numeric_literals.carbon b/toolchain/lex/testdata/numeric_literals.carbon
index cd39bd13f238..46cdd759c5d3 100644
--- a/toolchain/lex/testdata/numeric_literals.carbon
+++ b/toolchain/lex/testdata/numeric_literals.carbon
@@ -137,8 +137,9 @@ fn F() {
 // CHECK:STDOUT: - filename: fail_unknown_base.carbon
 // CHECK:STDOUT:   tokens:
 
-// CHECK:STDERR: fail_unknown_base.carbon:[[@LINE+3]]:1: error: unknown base specifier in numeric literal [UnknownBaseSpecifier]
+// CHECK:STDERR: fail_unknown_base.carbon:[[@LINE+4]]:1: error: unknown base specifier in numeric literal [UnknownBaseSpecifier]
 // CHECK:STDERR: 05
 // CHECK:STDERR: ^
+// CHECK:STDERR:
 05
 // CHECK:STDOUT:   - { index: 1, kind:     'Error', line: {{ *}}[[@LINE-1]], column:   1, indent: 1, spelling: '05', has_leading_space: true }
diff --git a/toolchain/lex/testdata/string_literals.carbon b/toolchain/lex/testdata/string_literals.carbon
index b8d4b9c7c905..f5956f4f1af1 100644
Binary files a/toolchain/lex/testdata/string_literals.carbon and b/toolchain/lex/testdata/string_literals.carbon differ
diff --git a/toolchain/lower/testdata/basics/fail_before_lowering.carbon b/toolchain/lower/testdata/basics/fail_before_lowering.carbon
index c5cde99a113f..563de99f6214 100644
--- a/toolchain/lower/testdata/basics/fail_before_lowering.carbon
+++ b/toolchain/lower/testdata/basics/fail_before_lowering.carbon
@@ -9,11 +9,12 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/lower/testdata/basics/fail_before_lowering.carbon
 
-// CHECK:STDERR: fail_before_lowering.carbon:[[@LINE+7]]:1: error: unrecognized declaration introducer [UnrecognizedDecl]
+// CHECK:STDERR: fail_before_lowering.carbon:[[@LINE+8]]:1: error: unrecognized declaration introducer [UnrecognizedDecl]
 // CHECK:STDERR: a;
 // CHECK:STDERR: ^
 // CHECK:STDERR:
-// CHECK:STDERR: fail_before_lowering.carbon:[[@LINE+3]]:1: error: semantics TODO: `handle invalid parse trees in `check`` [SemanticsTodo]
+// CHECK:STDERR: fail_before_lowering.carbon:[[@LINE+4]]:1: error: semantics TODO: `handle invalid parse trees in `check`` [SemanticsTodo]
 // CHECK:STDERR: a;
 // CHECK:STDERR: ^
+// CHECK:STDERR:
 a;
diff --git a/toolchain/parse/testdata/alias/fail_syntax.carbon b/toolchain/parse/testdata/alias/fail_syntax.carbon
index b00c42757c2b..ba07d7d40e1d 100644
--- a/toolchain/parse/testdata/alias/fail_syntax.carbon
+++ b/toolchain/parse/testdata/alias/fail_syntax.carbon
@@ -72,9 +72,10 @@ fn F() {
 
 alias a = b
 
-// CHECK:STDERR: fail_syntax.carbon:[[@LINE+56]]:21: error: `alias` declarations must end with a `;` [ExpectedDeclSemi]
+// CHECK:STDERR: fail_syntax.carbon:[[@LINE+57]]:21: error: `alias` declarations must end with a `;` [ExpectedDeclSemi]
 // CHECK:STDERR: // CHECK:STDOUT:   ]
 // CHECK:STDERR:                     ^
+// CHECK:STDERR:
 // CHECK:STDOUT: - filename: fail_syntax.carbon
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
diff --git a/toolchain/parse/testdata/array/fail_require_close_bracket.carbon b/toolchain/parse/testdata/array/fail_require_close_bracket.carbon
index 77584ce69bb7..3399060b7573 100644
--- a/toolchain/parse/testdata/array/fail_require_close_bracket.carbon
+++ b/toolchain/parse/testdata/array/fail_require_close_bracket.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/array/fail_require_close_bracket.carbon
 // TODO: It should emit only one error message.
 
-// CHECK:STDERR: fail_require_close_bracket.carbon:[[@LINE+3]]:8: error: opening symbol without a corresponding closing symbol [UnmatchedOpening]
+// CHECK:STDERR: fail_require_close_bracket.carbon:[[@LINE+4]]:8: error: opening symbol without a corresponding closing symbol [UnmatchedOpening]
 // CHECK:STDERR: var x: [i32;;
 // CHECK:STDERR:        ^
+// CHECK:STDERR:
 var x: [i32;;
 
 // CHECK:STDOUT: - filename: fail_require_close_bracket.carbon
diff --git a/toolchain/parse/testdata/array/fail_require_semi.carbon b/toolchain/parse/testdata/array/fail_require_semi.carbon
index a40746f9af74..442a724cf3e1 100644
--- a/toolchain/parse/testdata/array/fail_require_semi.carbon
+++ b/toolchain/parse/testdata/array/fail_require_semi.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/array/fail_require_semi.carbon
 
-// CHECK:STDERR: fail_require_semi.carbon:[[@LINE+3]]:12: error: expected `;` in array type [ExpectedArraySemi]
+// CHECK:STDERR: fail_require_semi.carbon:[[@LINE+4]]:12: error: expected `;` in array type [ExpectedArraySemi]
 // CHECK:STDERR: var x: [i32];
 // CHECK:STDERR:            ^
+// CHECK:STDERR:
 var x: [i32];
 
 // CHECK:STDOUT: - filename: fail_require_semi.carbon
diff --git a/toolchain/parse/testdata/array/fail_syntax.carbon b/toolchain/parse/testdata/array/fail_syntax.carbon
index e3527b08e685..66d97e6bcfab 100644
--- a/toolchain/parse/testdata/array/fail_syntax.carbon
+++ b/toolchain/parse/testdata/array/fail_syntax.carbon
@@ -62,9 +62,10 @@ var x: [i32;;
 
 // --- fail_no_semi.carbon
 
-// CHECK:STDERR: fail_no_semi.carbon:[[@LINE+3]]:12: error: expected `;` in array type [ExpectedArraySemi]
+// CHECK:STDERR: fail_no_semi.carbon:[[@LINE+4]]:12: error: expected `;` in array type [ExpectedArraySemi]
 // CHECK:STDERR: var x: [i32];
 // CHECK:STDERR:            ^
+// CHECK:STDERR:
 var x: [i32];
 
 // CHECK:STDOUT: - filename: fail_type.carbon
diff --git a/toolchain/parse/testdata/basics/fail_bracket_recovery.carbon b/toolchain/parse/testdata/basics/fail_bracket_recovery.carbon
index af36800e4668..d661c2fd1af1 100644
--- a/toolchain/parse/testdata/basics/fail_bracket_recovery.carbon
+++ b/toolchain/parse/testdata/basics/fail_bracket_recovery.carbon
@@ -15,17 +15,18 @@ fn F() {
   // CHECK:STDERR:           ^
   // CHECK:STDERR:
   var x: ([i32; 3) = (0, 1, 2);
-  // CHECK:STDERR: fail_bracket_recovery.carbon:[[@LINE+11]]:15: error: opening symbol without a corresponding closing symbol [UnmatchedOpening]
+  // CHECK:STDERR: fail_bracket_recovery.carbon:[[@LINE+12]]:15: error: opening symbol without a corresponding closing symbol [UnmatchedOpening]
   // CHECK:STDERR:   var x: {.y: (} = {.y = ((};
   // CHECK:STDERR:               ^
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_bracket_recovery.carbon:[[@LINE+7]]:26: error: opening symbol without a corresponding closing symbol [UnmatchedOpening]
+  // CHECK:STDERR: fail_bracket_recovery.carbon:[[@LINE+8]]:26: error: opening symbol without a corresponding closing symbol [UnmatchedOpening]
   // CHECK:STDERR:   var x: {.y: (} = {.y = ((};
   // CHECK:STDERR:                          ^
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_bracket_recovery.carbon:[[@LINE+3]]:27: error: opening symbol without a corresponding closing symbol [UnmatchedOpening]
+  // CHECK:STDERR: fail_bracket_recovery.carbon:[[@LINE+4]]:27: error: opening symbol without a corresponding closing symbol [UnmatchedOpening]
   // CHECK:STDERR:   var x: {.y: (} = {.y = ((};
   // CHECK:STDERR:                           ^
+  // CHECK:STDERR:
   var x: {.y: (} = {.y = ((};
 }
 
diff --git a/toolchain/parse/testdata/basics/fail_invalid_designators.carbon b/toolchain/parse/testdata/basics/fail_invalid_designators.carbon
index 29ab7997f05e..40c4be50bc11 100644
--- a/toolchain/parse/testdata/basics/fail_invalid_designators.carbon
+++ b/toolchain/parse/testdata/basics/fail_invalid_designators.carbon
@@ -15,9 +15,10 @@ fn F() {
   // CHECK:STDERR:     ^
   // CHECK:STDERR:
   a.;
-  // CHECK:STDERR: fail_invalid_designators.carbon:[[@LINE+3]]:5: error: expected identifier after `.` [ExpectedIdentifierAfterPeriodOrArrow]
+  // CHECK:STDERR: fail_invalid_designators.carbon:[[@LINE+4]]:5: error: expected identifier after `.` [ExpectedIdentifierAfterPeriodOrArrow]
   // CHECK:STDERR:   a.fn;
   // CHECK:STDERR:     ^~
+  // CHECK:STDERR:
   a.fn;
 }
 
diff --git a/toolchain/parse/testdata/basics/fail_modifiers_before_semi.carbon b/toolchain/parse/testdata/basics/fail_modifiers_before_semi.carbon
index f07dc53fc4eb..47c48cb94046 100644
--- a/toolchain/parse/testdata/basics/fail_modifiers_before_semi.carbon
+++ b/toolchain/parse/testdata/basics/fail_modifiers_before_semi.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/basics/fail_modifiers_before_semi.carbon
 
-// CHECK:STDERR: fail_modifiers_before_semi.carbon:[[@LINE+3]]:18: error: unrecognized declaration introducer [UnrecognizedDecl]
+// CHECK:STDERR: fail_modifiers_before_semi.carbon:[[@LINE+4]]:18: error: unrecognized declaration introducer [UnrecognizedDecl]
 // CHECK:STDERR: protected virtual;
 // CHECK:STDERR:                  ^
+// CHECK:STDERR:
 protected virtual;
 
 // CHECK:STDOUT: - filename: fail_modifiers_before_semi.carbon
diff --git a/toolchain/parse/testdata/basics/fail_no_intro_with_semi.carbon b/toolchain/parse/testdata/basics/fail_no_intro_with_semi.carbon
index 8370169ccf5c..b2c98ba33873 100644
--- a/toolchain/parse/testdata/basics/fail_no_intro_with_semi.carbon
+++ b/toolchain/parse/testdata/basics/fail_no_intro_with_semi.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/basics/fail_no_intro_with_semi.carbon
 
-// CHECK:STDERR: fail_no_intro_with_semi.carbon:[[@LINE+3]]:1: error: unrecognized declaration introducer [UnrecognizedDecl]
+// CHECK:STDERR: fail_no_intro_with_semi.carbon:[[@LINE+4]]:1: error: unrecognized declaration introducer [UnrecognizedDecl]
 // CHECK:STDERR: foo;
 // CHECK:STDERR: ^~~
+// CHECK:STDERR:
 foo;
 
 // CHECK:STDOUT: - filename: fail_no_intro_with_semi.carbon
diff --git a/toolchain/parse/testdata/basics/fail_no_intro_without_semi.carbon b/toolchain/parse/testdata/basics/fail_no_intro_without_semi.carbon
index 3d119b08615d..b57604bebdb2 100644
--- a/toolchain/parse/testdata/basics/fail_no_intro_without_semi.carbon
+++ b/toolchain/parse/testdata/basics/fail_no_intro_without_semi.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/basics/fail_no_intro_without_semi.carbon
 
-// CHECK:STDERR: fail_no_intro_without_semi.carbon:[[@LINE+3]]:1: error: unrecognized declaration introducer [UnrecognizedDecl]
+// CHECK:STDERR: fail_no_intro_without_semi.carbon:[[@LINE+4]]:1: error: unrecognized declaration introducer [UnrecognizedDecl]
 // CHECK:STDERR: foo bar baz
 // CHECK:STDERR: ^~~
+// CHECK:STDERR:
 foo bar baz
 
 // CHECK:STDOUT: - filename: fail_no_intro_without_semi.carbon
diff --git a/toolchain/parse/testdata/basics/fail_paren_match_regression.carbon b/toolchain/parse/testdata/basics/fail_paren_match_regression.carbon
index 0003b7339bc8..b80023bf6337 100644
--- a/toolchain/parse/testdata/basics/fail_paren_match_regression.carbon
+++ b/toolchain/parse/testdata/basics/fail_paren_match_regression.carbon
@@ -18,9 +18,10 @@
 // CHECK:STDERR:
 var = (foo {})
 
-// CHECK:STDERR: fail_paren_match_regression.carbon:[[@LINE+16]]:21: error: `var` declarations must end with a `;` [ExpectedDeclSemi]
+// CHECK:STDERR: fail_paren_match_regression.carbon:[[@LINE+17]]:21: error: `var` declarations must end with a `;` [ExpectedDeclSemi]
 // CHECK:STDERR: // CHECK:STDOUT:   ]
 // CHECK:STDERR:                     ^
+// CHECK:STDERR:
 // CHECK:STDOUT: - filename: fail_paren_match_regression.carbon
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
diff --git a/toolchain/parse/testdata/choice/fail_alternative_with_implicit_params.carbon b/toolchain/parse/testdata/choice/fail_alternative_with_implicit_params.carbon
index 0f42830d1be5..1ff7149a1ab4 100644
--- a/toolchain/parse/testdata/choice/fail_alternative_with_implicit_params.carbon
+++ b/toolchain/parse/testdata/choice/fail_alternative_with_implicit_params.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/choice/fail_alternative_with_implicit_params.carbon
 
 choice X {
-  // CHECK:STDERR: fail_alternative_with_implicit_params.carbon:[[@LINE+3]]:4: error: expected `,` or `}` [UnexpectedTokenAfterListElement]
+  // CHECK:STDERR: fail_alternative_with_implicit_params.carbon:[[@LINE+4]]:4: error: expected `,` or `}` [UnexpectedTokenAfterListElement]
   // CHECK:STDERR:   A[T:! type](value: T)
   // CHECK:STDERR:    ^
+  // CHECK:STDERR:
   A[T:! type](value: T)
 }
 
diff --git a/toolchain/parse/testdata/choice/fail_invalid_alternative_identifier.carbon b/toolchain/parse/testdata/choice/fail_invalid_alternative_identifier.carbon
index 77e8d5b656bf..3fa675992d63 100644
--- a/toolchain/parse/testdata/choice/fail_invalid_alternative_identifier.carbon
+++ b/toolchain/parse/testdata/choice/fail_invalid_alternative_identifier.carbon
@@ -14,9 +14,10 @@ choice InvalidAlternativeIdentifier {
     // CHECK:STDERR:     ^
     // CHECK:STDERR:
     ,Some,
-    // CHECK:STDERR: fail_invalid_alternative_identifier.carbon:[[@LINE+3]]:5: error: expected choice alternative name [ExpectedChoiceAlternativeName]
+    // CHECK:STDERR: fail_invalid_alternative_identifier.carbon:[[@LINE+4]]:5: error: expected choice alternative name [ExpectedChoiceAlternativeName]
     // CHECK:STDERR:     42,
     // CHECK:STDERR:     ^~
+    // CHECK:STDERR:
     42,
     Other
 }
diff --git a/toolchain/parse/testdata/choice/fail_invalid_braces.carbon b/toolchain/parse/testdata/choice/fail_invalid_braces.carbon
index d1180d1f86b9..c89711bba189 100644
--- a/toolchain/parse/testdata/choice/fail_invalid_braces.carbon
+++ b/toolchain/parse/testdata/choice/fail_invalid_braces.carbon
@@ -14,9 +14,10 @@
 // CHECK:STDERR:
 choice InvalidBraces |
   Some
-// CHECK:STDERR: fail_invalid_braces.carbon:[[@LINE+3]]:1: error: unrecognized declaration introducer [UnrecognizedDecl]
+// CHECK:STDERR: fail_invalid_braces.carbon:[[@LINE+4]]:1: error: unrecognized declaration introducer [UnrecognizedDecl]
 // CHECK:STDERR: |
 // CHECK:STDERR: ^
+// CHECK:STDERR:
 |
 
 // CHECK:STDOUT: - filename: fail_invalid_braces.carbon
diff --git a/toolchain/parse/testdata/choice/fail_missing_definition.carbon b/toolchain/parse/testdata/choice/fail_missing_definition.carbon
index 2d23da8fabd9..4b1920d4854a 100644
--- a/toolchain/parse/testdata/choice/fail_missing_definition.carbon
+++ b/toolchain/parse/testdata/choice/fail_missing_definition.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/choice/fail_missing_definition.carbon
 
-// CHECK:STDERR: fail_missing_definition.carbon:[[@LINE+3]]:25: error: choice definition expected [ExpectedChoiceDefinition]
+// CHECK:STDERR: fail_missing_definition.carbon:[[@LINE+4]]:25: error: choice definition expected [ExpectedChoiceDefinition]
 // CHECK:STDERR: choice MissingDefinition;
 // CHECK:STDERR:                         ^
+// CHECK:STDERR:
 choice MissingDefinition;
 
 // CHECK:STDOUT: - filename: fail_missing_definition.carbon
diff --git a/toolchain/parse/testdata/choice/fail_missing_definition_parameterized.carbon b/toolchain/parse/testdata/choice/fail_missing_definition_parameterized.carbon
index 3f0148858904..b5ba62f42bc1 100644
--- a/toolchain/parse/testdata/choice/fail_missing_definition_parameterized.carbon
+++ b/toolchain/parse/testdata/choice/fail_missing_definition_parameterized.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/choice/fail_missing_definition_parameterized.carbon
 
-// CHECK:STDERR: fail_missing_definition_parameterized.carbon:[[@LINE+3]]:35: error: choice definition expected [ExpectedChoiceDefinition]
+// CHECK:STDERR: fail_missing_definition_parameterized.carbon:[[@LINE+4]]:35: error: choice definition expected [ExpectedChoiceDefinition]
 // CHECK:STDERR: choice MissingDefinition(T:! type);
 // CHECK:STDERR:                                   ^
+// CHECK:STDERR:
 choice MissingDefinition(T:! type);
 
 // CHECK:STDOUT: - filename: fail_missing_definition_parameterized.carbon
diff --git a/toolchain/parse/testdata/choice/fail_qualified_alternative_name.carbon b/toolchain/parse/testdata/choice/fail_qualified_alternative_name.carbon
index c3f3fc08ac69..c1e7409c0ca6 100644
--- a/toolchain/parse/testdata/choice/fail_qualified_alternative_name.carbon
+++ b/toolchain/parse/testdata/choice/fail_qualified_alternative_name.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/choice/fail_qualified_alternative_name.carbon
 
 choice X {
-  // CHECK:STDERR: fail_qualified_alternative_name.carbon:[[@LINE+3]]:4: error: expected `,` or `}` [UnexpectedTokenAfterListElement]
+  // CHECK:STDERR: fail_qualified_alternative_name.carbon:[[@LINE+4]]:4: error: expected `,` or `}` [UnexpectedTokenAfterListElement]
   // CHECK:STDERR:   A.B
   // CHECK:STDERR:    ^
+  // CHECK:STDERR:
   A.B
 }
 
diff --git a/toolchain/parse/testdata/class/adapt.carbon b/toolchain/parse/testdata/class/adapt.carbon
index 2d3b64f61301..4a2efdb02753 100644
--- a/toolchain/parse/testdata/class/adapt.carbon
+++ b/toolchain/parse/testdata/class/adapt.carbon
@@ -60,9 +60,10 @@ class C {
 }
 
 class D {
-  // CHECK:STDERR: fail_bad_syntax.carbon:[[@LINE+3]]:9: error: expected expression [ExpectedExpr]
+  // CHECK:STDERR: fail_bad_syntax.carbon:[[@LINE+4]]:9: error: expected expression [ExpectedExpr]
   // CHECK:STDERR:   adapt class;
   // CHECK:STDERR:         ^~~~~
+  // CHECK:STDERR:
   adapt class;
 }
 
diff --git a/toolchain/parse/testdata/class/fail_base.carbon b/toolchain/parse/testdata/class/fail_base.carbon
index 97d4ae62208b..bb2cc1f1cc08 100644
--- a/toolchain/parse/testdata/class/fail_base.carbon
+++ b/toolchain/parse/testdata/class/fail_base.carbon
@@ -23,13 +23,14 @@ class A {
 
   base: { }
   // We should resume parsing here after the previous error.
-  // CHECK:STDERR: fail_base.carbon:[[@LINE+7]]:3: error: `base` declarations must end with a `;` [ExpectedDeclSemi]
+  // CHECK:STDERR: fail_base.carbon:[[@LINE+8]]:3: error: `base` declarations must end with a `;` [ExpectedDeclSemi]
   // CHECK:STDERR:   var n: i32;
   // CHECK:STDERR:   ^~~
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_base.carbon:[[@LINE+3]]:7: error: unrecognized declaration introducer [UnrecognizedDecl]
+  // CHECK:STDERR: fail_base.carbon:[[@LINE+4]]:7: error: unrecognized declaration introducer [UnrecognizedDecl]
   // CHECK:STDERR:   var n: i32;
   // CHECK:STDERR:       ^
+  // CHECK:STDERR:
   var n: i32;
 }
 
diff --git a/toolchain/parse/testdata/class/fail_modifiers.carbon b/toolchain/parse/testdata/class/fail_modifiers.carbon
index d636e9d7e1d1..68758e96c75e 100644
--- a/toolchain/parse/testdata/class/fail_modifiers.carbon
+++ b/toolchain/parse/testdata/class/fail_modifiers.carbon
@@ -27,9 +27,10 @@ impl class
 // --- fail_extend_adapt_base.carbon
 
 class C {
-  // CHECK:STDERR: fail_extend_adapt_base.carbon:[[@LINE+3]]:16: error: expected expression [ExpectedExpr]
+  // CHECK:STDERR: fail_extend_adapt_base.carbon:[[@LINE+4]]:16: error: expected expression [ExpectedExpr]
   // CHECK:STDERR:   extend adapt base B;
   // CHECK:STDERR:                ^~~~
+  // CHECK:STDERR:
   extend adapt base B;
 }
 
diff --git a/toolchain/parse/testdata/for/fail_colon_instead_of_in.carbon b/toolchain/parse/testdata/for/fail_colon_instead_of_in.carbon
index 42291f69d96f..5ddd3f31649b 100644
--- a/toolchain/parse/testdata/for/fail_colon_instead_of_in.carbon
+++ b/toolchain/parse/testdata/for/fail_colon_instead_of_in.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/for/fail_colon_instead_of_in.carbon
 
 fn foo() {
-  // CHECK:STDERR: fail_colon_instead_of_in.carbon:[[@LINE+3]]:19: error: `:` should be replaced by `in` [ExpectedInNotColon]
+  // CHECK:STDERR: fail_colon_instead_of_in.carbon:[[@LINE+4]]:19: error: `:` should be replaced by `in` [ExpectedInNotColon]
   // CHECK:STDERR:   for (var x: i32 : y) {
   // CHECK:STDERR:                   ^
+  // CHECK:STDERR:
   for (var x: i32 : y) {
     Print(x);
   }
diff --git a/toolchain/parse/testdata/for/fail_missing_cond.carbon b/toolchain/parse/testdata/for/fail_missing_cond.carbon
index 9fb55398e01c..0bf46d24d6b8 100644
--- a/toolchain/parse/testdata/for/fail_missing_cond.carbon
+++ b/toolchain/parse/testdata/for/fail_missing_cond.carbon
@@ -19,13 +19,14 @@ fn F() {
   // CHECK:STDERR:
   for {
   }
-// CHECK:STDERR: fail_missing_cond.carbon:[[@LINE+7]]:1: error: expected braced code block [ExpectedCodeBlock]
+// CHECK:STDERR: fail_missing_cond.carbon:[[@LINE+8]]:1: error: expected braced code block [ExpectedCodeBlock]
 // CHECK:STDERR: }
 // CHECK:STDERR: ^
 // CHECK:STDERR:
-// CHECK:STDERR: fail_missing_cond.carbon:[[@LINE+3]]:1: error: expected expression [ExpectedExpr]
+// CHECK:STDERR: fail_missing_cond.carbon:[[@LINE+4]]:1: error: expected expression [ExpectedExpr]
 // CHECK:STDERR: }
 // CHECK:STDERR: ^
+// CHECK:STDERR:
 }
 
 // CHECK:STDOUT: - filename: fail_missing_cond.carbon
diff --git a/toolchain/parse/testdata/for/fail_missing_in.carbon b/toolchain/parse/testdata/for/fail_missing_in.carbon
index 30c848a9e0e2..f7fe27a11625 100644
--- a/toolchain/parse/testdata/for/fail_missing_in.carbon
+++ b/toolchain/parse/testdata/for/fail_missing_in.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/for/fail_missing_in.carbon
 
 fn foo() {
-  // CHECK:STDERR: fail_missing_in.carbon:[[@LINE+3]]:19: error: expected `in` after loop `var` declaration [ExpectedIn]
+  // CHECK:STDERR: fail_missing_in.carbon:[[@LINE+4]]:19: error: expected `in` after loop `var` declaration [ExpectedIn]
   // CHECK:STDERR:   for (var x: i32 y) {
   // CHECK:STDERR:                   ^
+  // CHECK:STDERR:
   for (var x: i32 y) {
     Print(x);
   }
diff --git a/toolchain/parse/testdata/for/fail_missing_var.carbon b/toolchain/parse/testdata/for/fail_missing_var.carbon
index cbe47c6f3d9f..6d8640cb345b 100644
--- a/toolchain/parse/testdata/for/fail_missing_var.carbon
+++ b/toolchain/parse/testdata/for/fail_missing_var.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/for/fail_missing_var.carbon
 
 fn foo() {
-  // CHECK:STDERR: fail_missing_var.carbon:[[@LINE+3]]:8: error: expected `var` declaration [ExpectedVariableDecl]
+  // CHECK:STDERR: fail_missing_var.carbon:[[@LINE+4]]:8: error: expected `var` declaration [ExpectedVariableDecl]
   // CHECK:STDERR:   for (x: i32 in y) {
   // CHECK:STDERR:        ^
+  // CHECK:STDERR:
   for (x: i32 in y) {
     Print(x);
   }
diff --git a/toolchain/parse/testdata/for/fail_returned_var.carbon b/toolchain/parse/testdata/for/fail_returned_var.carbon
index f7da37a5b825..fc876bba70a1 100644
--- a/toolchain/parse/testdata/for/fail_returned_var.carbon
+++ b/toolchain/parse/testdata/for/fail_returned_var.carbon
@@ -10,9 +10,10 @@
 
 fn foo() -> i32 {
   // TODO: Should we allow this?
-  // CHECK:STDERR: fail_returned_var.carbon:[[@LINE+3]]:8: error: expected `var` declaration [ExpectedVariableDecl]
+  // CHECK:STDERR: fail_returned_var.carbon:[[@LINE+4]]:8: error: expected `var` declaration [ExpectedVariableDecl]
   // CHECK:STDERR:   for (returned var x: i32 in y) {
   // CHECK:STDERR:        ^~~~~~~~
+  // CHECK:STDERR:
   for (returned var x: i32 in y) {
     return var;
   }
diff --git a/toolchain/parse/testdata/for/fail_square_brackets.carbon b/toolchain/parse/testdata/for/fail_square_brackets.carbon
index df4447e57175..a5f595a66fb3 100644
--- a/toolchain/parse/testdata/for/fail_square_brackets.carbon
+++ b/toolchain/parse/testdata/for/fail_square_brackets.carbon
@@ -9,21 +9,22 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/for/fail_square_brackets.carbon
 
 fn F() {
-  // CHECK:STDERR: fail_square_brackets.carbon:[[@LINE+15]]:7: error: expected `(` after `for` [ExpectedParenAfter]
+  // CHECK:STDERR: fail_square_brackets.carbon:[[@LINE+16]]:7: error: expected `(` after `for` [ExpectedParenAfter]
   // CHECK:STDERR:   for [] {
   // CHECK:STDERR:       ^
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_square_brackets.carbon:[[@LINE+11]]:7: error: expected `var` declaration [ExpectedVariableDecl]
+  // CHECK:STDERR: fail_square_brackets.carbon:[[@LINE+12]]:7: error: expected `var` declaration [ExpectedVariableDecl]
   // CHECK:STDERR:   for [] {
   // CHECK:STDERR:       ^
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_square_brackets.carbon:[[@LINE+7]]:8: error: expected expression [ExpectedExpr]
+  // CHECK:STDERR: fail_square_brackets.carbon:[[@LINE+8]]:8: error: expected expression [ExpectedExpr]
   // CHECK:STDERR:   for [] {
   // CHECK:STDERR:        ^
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_square_brackets.carbon:[[@LINE+3]]:8: error: expected `;` in array type [ExpectedArraySemi]
+  // CHECK:STDERR: fail_square_brackets.carbon:[[@LINE+4]]:8: error: expected `;` in array type [ExpectedArraySemi]
   // CHECK:STDERR:   for [] {
   // CHECK:STDERR:        ^
+  // CHECK:STDERR:
   for [] {
   }
 }
diff --git a/toolchain/parse/testdata/function/declaration/extern.carbon b/toolchain/parse/testdata/function/declaration/extern.carbon
index af6f6d8a276f..ab6c8049daee 100644
--- a/toolchain/parse/testdata/function/declaration/extern.carbon
+++ b/toolchain/parse/testdata/function/declaration/extern.carbon
@@ -30,13 +30,14 @@ extern library fn G();
 
 // --- fail_identifier.carbon
 
-// CHECK:STDERR: fail_identifier.carbon:[[@LINE+7]]:16: error: expected `default` or a string literal to specify the library name [ExpectedLibraryNameOrDefault]
+// CHECK:STDERR: fail_identifier.carbon:[[@LINE+8]]:16: error: expected `default` or a string literal to specify the library name [ExpectedLibraryNameOrDefault]
 // CHECK:STDERR: extern library foo fn G();
 // CHECK:STDERR:                ^~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_identifier.carbon:[[@LINE+3]]:16: error: unrecognized declaration introducer [UnrecognizedDecl]
+// CHECK:STDERR: fail_identifier.carbon:[[@LINE+4]]:16: error: unrecognized declaration introducer [UnrecognizedDecl]
 // CHECK:STDERR: extern library foo fn G();
 // CHECK:STDERR:                ^~~
+// CHECK:STDERR:
 extern library foo fn G();
 
 // CHECK:STDOUT: - filename: extern.carbon
diff --git a/toolchain/parse/testdata/function/declaration/fail_identifier_instead_of_sig.carbon b/toolchain/parse/testdata/function/declaration/fail_identifier_instead_of_sig.carbon
index 4e22b2268bb2..faeed0a495bb 100644
--- a/toolchain/parse/testdata/function/declaration/fail_identifier_instead_of_sig.carbon
+++ b/toolchain/parse/testdata/function/declaration/fail_identifier_instead_of_sig.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/function/declaration/fail_identifier_instead_of_sig.carbon
 
-// CHECK:STDERR: fail_identifier_instead_of_sig.carbon:[[@LINE+3]]:8: error: `fn` declarations must either end with a `;` or have a `{ ... }` block for a definition [ExpectedDeclSemiOrDefinition]
+// CHECK:STDERR: fail_identifier_instead_of_sig.carbon:[[@LINE+4]]:8: error: `fn` declarations must either end with a `;` or have a `{ ... }` block for a definition [ExpectedDeclSemiOrDefinition]
 // CHECK:STDERR: fn foo bar;
 // CHECK:STDERR:        ^~~
+// CHECK:STDERR:
 fn foo bar;
 
 // CHECK:STDOUT: - filename: fail_identifier_instead_of_sig.carbon
diff --git a/toolchain/parse/testdata/function/declaration/fail_missing_implicit_close.carbon b/toolchain/parse/testdata/function/declaration/fail_missing_implicit_close.carbon
index be0d9dba9085..719c393789ad 100644
--- a/toolchain/parse/testdata/function/declaration/fail_missing_implicit_close.carbon
+++ b/toolchain/parse/testdata/function/declaration/fail_missing_implicit_close.carbon
@@ -9,13 +9,14 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/function/declaration/fail_missing_implicit_close.carbon
 
 // Fix and uncomment this to test error handling.
-// CHECK:STDERR: fail_missing_implicit_close.carbon:[[@LINE+7]]:7: error: opening symbol without a corresponding closing symbol [UnmatchedOpening]
+// CHECK:STDERR: fail_missing_implicit_close.carbon:[[@LINE+8]]:7: error: opening symbol without a corresponding closing symbol [UnmatchedOpening]
 // CHECK:STDERR: fn Div[();
 // CHECK:STDERR:       ^
 // CHECK:STDERR:
-// CHECK:STDERR: fail_missing_implicit_close.carbon:[[@LINE+3]]:7: error: `fn` declarations must either end with a `;` or have a `{ ... }` block for a definition [ExpectedDeclSemiOrDefinition]
+// CHECK:STDERR: fail_missing_implicit_close.carbon:[[@LINE+4]]:7: error: `fn` declarations must either end with a `;` or have a `{ ... }` block for a definition [ExpectedDeclSemiOrDefinition]
 // CHECK:STDERR: fn Div[();
 // CHECK:STDERR:       ^
+// CHECK:STDERR:
 fn Div[();
 
 // CHECK:STDOUT: - filename: fail_missing_implicit_close.carbon
diff --git a/toolchain/parse/testdata/function/declaration/fail_missing_name.carbon b/toolchain/parse/testdata/function/declaration/fail_missing_name.carbon
index 2abab4230d57..d71fc4b01eca 100644
--- a/toolchain/parse/testdata/function/declaration/fail_missing_name.carbon
+++ b/toolchain/parse/testdata/function/declaration/fail_missing_name.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/function/declaration/fail_missing_name.carbon
 
-// CHECK:STDERR: fail_missing_name.carbon:[[@LINE+3]]:4: error: `fn` introducer should be followed by a name [ExpectedDeclName]
+// CHECK:STDERR: fail_missing_name.carbon:[[@LINE+4]]:4: error: `fn` introducer should be followed by a name [ExpectedDeclName]
 // CHECK:STDERR: fn ();
 // CHECK:STDERR:    ^
+// CHECK:STDERR:
 fn ();
 
 // CHECK:STDOUT: - filename: fail_missing_name.carbon
diff --git a/toolchain/parse/testdata/function/declaration/fail_no_sig_or_semi.carbon b/toolchain/parse/testdata/function/declaration/fail_no_sig_or_semi.carbon
index 63a9e0ee5425..b74fb4b2aefd 100644
--- a/toolchain/parse/testdata/function/declaration/fail_no_sig_or_semi.carbon
+++ b/toolchain/parse/testdata/function/declaration/fail_no_sig_or_semi.carbon
@@ -10,9 +10,10 @@
 
 fn foo
 
-// CHECK:STDERR: fail_no_sig_or_semi.carbon:[[@LINE+10]]:21: error: `fn` declarations must either end with a `;` or have a `{ ... }` block for a definition [ExpectedDeclSemiOrDefinition]
+// CHECK:STDERR: fail_no_sig_or_semi.carbon:[[@LINE+11]]:21: error: `fn` declarations must either end with a `;` or have a `{ ... }` block for a definition [ExpectedDeclSemiOrDefinition]
 // CHECK:STDERR: // CHECK:STDOUT:   ]
 // CHECK:STDERR:                     ^
+// CHECK:STDERR:
 // CHECK:STDOUT: - filename: fail_no_sig_or_semi.carbon
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
diff --git a/toolchain/parse/testdata/function/declaration/fail_only_fn_and_semi.carbon b/toolchain/parse/testdata/function/declaration/fail_only_fn_and_semi.carbon
index cb9b61630975..08286af1ae52 100644
--- a/toolchain/parse/testdata/function/declaration/fail_only_fn_and_semi.carbon
+++ b/toolchain/parse/testdata/function/declaration/fail_only_fn_and_semi.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/function/declaration/fail_only_fn_and_semi.carbon
 
-// CHECK:STDERR: fail_only_fn_and_semi.carbon:[[@LINE+3]]:3: error: `fn` introducer should be followed by a name [ExpectedDeclName]
+// CHECK:STDERR: fail_only_fn_and_semi.carbon:[[@LINE+4]]:3: error: `fn` introducer should be followed by a name [ExpectedDeclName]
 // CHECK:STDERR: fn;
 // CHECK:STDERR:   ^
+// CHECK:STDERR:
 fn;
 
 // CHECK:STDOUT: - filename: fail_only_fn_and_semi.carbon
diff --git a/toolchain/parse/testdata/function/declaration/fail_repeated_fn_and_semi.carbon b/toolchain/parse/testdata/function/declaration/fail_repeated_fn_and_semi.carbon
index 0d133480882c..dc423b057bf3 100644
--- a/toolchain/parse/testdata/function/declaration/fail_repeated_fn_and_semi.carbon
+++ b/toolchain/parse/testdata/function/declaration/fail_repeated_fn_and_semi.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/function/declaration/fail_repeated_fn_and_semi.carbon
 
-// CHECK:STDERR: fail_repeated_fn_and_semi.carbon:[[@LINE+3]]:4: error: `fn` introducer should be followed by a name [ExpectedDeclName]
+// CHECK:STDERR: fail_repeated_fn_and_semi.carbon:[[@LINE+4]]:4: error: `fn` introducer should be followed by a name [ExpectedDeclName]
 // CHECK:STDERR: fn fn;
 // CHECK:STDERR:    ^~
+// CHECK:STDERR:
 fn fn;
 
 // CHECK:STDOUT: - filename: fail_repeated_fn_and_semi.carbon
diff --git a/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_until_outdent.carbon b/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_until_outdent.carbon
index a7e84e1baba4..2fd6f9a16719 100644
--- a/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_until_outdent.carbon
+++ b/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_until_outdent.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_until_outdent.carbon
 
-  // CHECK:STDERR: fail_skip_indented_newline_until_outdent.carbon:[[@LINE+3]]:6: error: `fn` introducer should be followed by a name [ExpectedDeclName]
+  // CHECK:STDERR: fail_skip_indented_newline_until_outdent.carbon:[[@LINE+4]]:6: error: `fn` introducer should be followed by a name [ExpectedDeclName]
   // CHECK:STDERR:   fn (x,
   // CHECK:STDERR:      ^
+  // CHECK:STDERR:
   fn (x,
       y,
       z)
diff --git a/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_with_semi.carbon b/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_with_semi.carbon
index a49ecc8b4af7..7f6c04d36831 100644
--- a/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_with_semi.carbon
+++ b/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_with_semi.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_with_semi.carbon
 
-// CHECK:STDERR: fail_skip_indented_newline_with_semi.carbon:[[@LINE+3]]:4: error: `fn` introducer should be followed by a name [ExpectedDeclName]
+// CHECK:STDERR: fail_skip_indented_newline_with_semi.carbon:[[@LINE+4]]:4: error: `fn` introducer should be followed by a name [ExpectedDeclName]
 // CHECK:STDERR: fn (x,
 // CHECK:STDERR:    ^
+// CHECK:STDERR:
 fn (x,
     y,
     z);
diff --git a/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_without_semi.carbon b/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_without_semi.carbon
index 367cc3fe5fc9..df96cbecac06 100644
--- a/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_without_semi.carbon
+++ b/toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_without_semi.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/function/declaration/fail_skip_indented_newline_without_semi.carbon
 
-// CHECK:STDERR: fail_skip_indented_newline_without_semi.carbon:[[@LINE+3]]:4: error: `fn` introducer should be followed by a name [ExpectedDeclName]
+// CHECK:STDERR: fail_skip_indented_newline_without_semi.carbon:[[@LINE+4]]:4: error: `fn` introducer should be followed by a name [ExpectedDeclName]
 // CHECK:STDERR: fn (x,
 // CHECK:STDERR:    ^
+// CHECK:STDERR:
 fn (x,
     y,
     z)
diff --git a/toolchain/parse/testdata/function/declaration/fail_skip_to_newline_without_semi.carbon b/toolchain/parse/testdata/function/declaration/fail_skip_to_newline_without_semi.carbon
index 569f33ba28fc..7f2585ae6c00 100644
--- a/toolchain/parse/testdata/function/declaration/fail_skip_to_newline_without_semi.carbon
+++ b/toolchain/parse/testdata/function/declaration/fail_skip_to_newline_without_semi.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/function/declaration/fail_skip_to_newline_without_semi.carbon
 
-// CHECK:STDERR: fail_skip_to_newline_without_semi.carbon:[[@LINE+3]]:4: error: `fn` introducer should be followed by a name [ExpectedDeclName]
+// CHECK:STDERR: fail_skip_to_newline_without_semi.carbon:[[@LINE+4]]:4: error: `fn` introducer should be followed by a name [ExpectedDeclName]
 // CHECK:STDERR: fn ()
 // CHECK:STDERR:    ^
+// CHECK:STDERR:
 fn ()
 fn F();
 
diff --git a/toolchain/parse/testdata/function/declaration/fail_skip_without_semi_to_curly.carbon b/toolchain/parse/testdata/function/declaration/fail_skip_without_semi_to_curly.carbon
index d63d38f1ff1d..6ec74baac1ff 100644
--- a/toolchain/parse/testdata/function/declaration/fail_skip_without_semi_to_curly.carbon
+++ b/toolchain/parse/testdata/function/declaration/fail_skip_without_semi_to_curly.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/function/declaration/fail_skip_without_semi_to_curly.carbon
 
-// CHECK:STDERR: fail_skip_without_semi_to_curly.carbon:[[@LINE+3]]:1: error: unrecognized declaration introducer [UnrecognizedDecl]
+// CHECK:STDERR: fail_skip_without_semi_to_curly.carbon:[[@LINE+4]]:1: error: unrecognized declaration introducer [UnrecognizedDecl]
 // CHECK:STDERR: struct X { fn () }
 // CHECK:STDERR: ^~~~~~
+// CHECK:STDERR:
 struct X { fn () }
 fn F();
 
diff --git a/toolchain/parse/testdata/function/declaration/fail_with_identifier_as_param.carbon b/toolchain/parse/testdata/function/declaration/fail_with_identifier_as_param.carbon
index 029da10ad245..034048656208 100644
--- a/toolchain/parse/testdata/function/declaration/fail_with_identifier_as_param.carbon
+++ b/toolchain/parse/testdata/function/declaration/fail_with_identifier_as_param.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/function/declaration/fail_with_identifier_as_param.carbon
 
-// CHECK:STDERR: fail_with_identifier_as_param.carbon:[[@LINE+3]]:11: error: expected `:` or `:!` in binding pattern [ExpectedBindingPattern]
+// CHECK:STDERR: fail_with_identifier_as_param.carbon:[[@LINE+4]]:11: error: expected `:` or `:!` in binding pattern [ExpectedBindingPattern]
 // CHECK:STDERR: fn foo(bar);
 // CHECK:STDERR:           ^
+// CHECK:STDERR:
 fn foo(bar);
 
 // CHECK:STDOUT: - filename: fail_with_identifier_as_param.carbon
diff --git a/toolchain/parse/testdata/function/declaration/fail_without_name_and_many_tokens_in_params.carbon b/toolchain/parse/testdata/function/declaration/fail_without_name_and_many_tokens_in_params.carbon
index 156db7e254de..d7c17fa26c57 100644
--- a/toolchain/parse/testdata/function/declaration/fail_without_name_and_many_tokens_in_params.carbon
+++ b/toolchain/parse/testdata/function/declaration/fail_without_name_and_many_tokens_in_params.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/function/declaration/fail_without_name_and_many_tokens_in_params.carbon
 
-// CHECK:STDERR: fail_without_name_and_many_tokens_in_params.carbon:[[@LINE+3]]:4: error: `fn` introducer should be followed by a name [ExpectedDeclName]
+// CHECK:STDERR: fail_without_name_and_many_tokens_in_params.carbon:[[@LINE+4]]:4: error: `fn` introducer should be followed by a name [ExpectedDeclName]
 // CHECK:STDERR: fn (a tokens c d e f g h i j k l m n o p q r s t u v w x y z);
 // CHECK:STDERR:    ^
+// CHECK:STDERR:
 fn (a tokens c d e f g h i j k l m n o p q r s t u v w x y z);
 
 // CHECK:STDOUT: - filename: fail_without_name_and_many_tokens_in_params.carbon
diff --git a/toolchain/parse/testdata/function/definition/fail_builtin.carbon b/toolchain/parse/testdata/function/definition/fail_builtin.carbon
index 7f10fe60f656..cba5b2052fae 100644
--- a/toolchain/parse/testdata/function/definition/fail_builtin.carbon
+++ b/toolchain/parse/testdata/function/definition/fail_builtin.carbon
@@ -19,9 +19,10 @@ fn NotString() = banana;
 // CHECK:STDERR:
 fn JunkAfterString() = "hello" "world";
 
-// CHECK:STDERR: fail_builtin.carbon:[[@LINE+3]]:23: error: expected builtin function name after `=` [ExpectedBuiltinName]
+// CHECK:STDERR: fail_builtin.carbon:[[@LINE+4]]:23: error: expected builtin function name after `=` [ExpectedBuiltinName]
 // CHECK:STDERR: fn SpuriousEquals() = { }
 // CHECK:STDERR:                       ^
+// CHECK:STDERR:
 fn SpuriousEquals() = { }
 fn TestRecoveryFromSpuriousEquals();
 
diff --git a/toolchain/parse/testdata/function/definition/fail_identifier_in_statements.carbon b/toolchain/parse/testdata/function/definition/fail_identifier_in_statements.carbon
index bdf83bbc4a20..622e10424ddd 100644
--- a/toolchain/parse/testdata/function/definition/fail_identifier_in_statements.carbon
+++ b/toolchain/parse/testdata/function/definition/fail_identifier_in_statements.carbon
@@ -12,9 +12,10 @@ fn F() {
   // Note: this might become valid depending on the expression syntax. This test
   // shouldn't be taken as a sign it should remain invalid.
   bar
-// CHECK:STDERR: fail_identifier_in_statements.carbon:[[@LINE+3]]:1: error: expected `;` after expression statement [ExpectedExprSemi]
+// CHECK:STDERR: fail_identifier_in_statements.carbon:[[@LINE+4]]:1: error: expected `;` after expression statement [ExpectedExprSemi]
 // CHECK:STDERR: }
 // CHECK:STDERR: ^
+// CHECK:STDERR:
 }
 
 // CHECK:STDOUT: - filename: fail_identifier_in_statements.carbon
diff --git a/toolchain/parse/testdata/generics/deduced_params/fail_no_parens.carbon b/toolchain/parse/testdata/generics/deduced_params/fail_no_parens.carbon
index 6df47948ff42..f87cb8337f6f 100644
--- a/toolchain/parse/testdata/generics/deduced_params/fail_no_parens.carbon
+++ b/toolchain/parse/testdata/generics/deduced_params/fail_no_parens.carbon
@@ -26,9 +26,10 @@ class Foo[a: i32];
 // CHECK:STDERR:
 interface Bar[] {}
 
-// CHECK:STDERR: fail_no_parens.carbon:[[@LINE+3]]:23: error: a `(` for parameters is required after implicit parameters [ParamsRequiredAfterImplicit]
+// CHECK:STDERR: fail_no_parens.carbon:[[@LINE+4]]:23: error: a `(` for parameters is required after implicit parameters [ParamsRequiredAfterImplicit]
 // CHECK:STDERR: interface Bar[a: i32] {}
 // CHECK:STDERR:                       ^
+// CHECK:STDERR:
 interface Bar[a: i32] {}
 
 // CHECK:STDOUT: - filename: fail_no_parens.carbon
diff --git a/toolchain/parse/testdata/generics/impl/fail_impl.carbon b/toolchain/parse/testdata/generics/impl/fail_impl.carbon
index 64b0a695f591..6dcd4c5f052e 100644
--- a/toolchain/parse/testdata/generics/impl/fail_impl.carbon
+++ b/toolchain/parse/testdata/generics/impl/fail_impl.carbon
@@ -96,9 +96,10 @@ impl;
 
 impl
 
-// CHECK:STDERR: fail_impl.carbon:[[@LINE+88]]:21: error: expected expression [ExpectedExpr]
+// CHECK:STDERR: fail_impl.carbon:[[@LINE+89]]:21: error: expected expression [ExpectedExpr]
 // CHECK:STDERR: // CHECK:STDOUT:   ]
 // CHECK:STDERR:                     ^
+// CHECK:STDERR:
 // CHECK:STDOUT: - filename: fail_impl.carbon
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
diff --git a/toolchain/parse/testdata/generics/impl/fail_out_of_line_member.carbon b/toolchain/parse/testdata/generics/impl/fail_out_of_line_member.carbon
index 63fb4337720e..83574fcb37ac 100644
--- a/toolchain/parse/testdata/generics/impl/fail_out_of_line_member.carbon
+++ b/toolchain/parse/testdata/generics/impl/fail_out_of_line_member.carbon
@@ -30,9 +30,10 @@ class C {
   }
 }
 
-// CHECK:STDERR: fail_out_of_line_member.carbon:[[@LINE+3]]:6: error: `.` should be followed by a name [ExpectedDeclNameAfterPeriod]
+// CHECK:STDERR: fail_out_of_line_member.carbon:[[@LINE+4]]:6: error: `.` should be followed by a name [ExpectedDeclNameAfterPeriod]
 // CHECK:STDERR: fn C.(Self as Interface).F() {}
 // CHECK:STDERR:      ^
+// CHECK:STDERR:
 fn C.(Self as Interface).F() {}
 
 // CHECK:STDOUT: - filename: fail_out_of_line_member.carbon
diff --git a/toolchain/parse/testdata/generics/interface/fail_missing_name.carbon b/toolchain/parse/testdata/generics/interface/fail_missing_name.carbon
index b37a609f7c5b..9ac540879e62 100644
--- a/toolchain/parse/testdata/generics/interface/fail_missing_name.carbon
+++ b/toolchain/parse/testdata/generics/interface/fail_missing_name.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/generics/interface/fail_missing_name.carbon
 
-// CHECK:STDERR: fail_missing_name.carbon:[[@LINE+3]]:11: error: `interface` introducer should be followed by a name [ExpectedDeclName]
+// CHECK:STDERR: fail_missing_name.carbon:[[@LINE+4]]:11: error: `interface` introducer should be followed by a name [ExpectedDeclName]
 // CHECK:STDERR: interface {
 // CHECK:STDERR:           ^
+// CHECK:STDERR:
 interface {
 }
 
diff --git a/toolchain/parse/testdata/generics/interface/fail_missing_open_curly.carbon b/toolchain/parse/testdata/generics/interface/fail_missing_open_curly.carbon
index 92dc39cc1af0..94e0b056ca0b 100644
--- a/toolchain/parse/testdata/generics/interface/fail_missing_open_curly.carbon
+++ b/toolchain/parse/testdata/generics/interface/fail_missing_open_curly.carbon
@@ -16,9 +16,10 @@ interface Bar Baz {}
 
 interface Foo
 
-// CHECK:STDERR: fail_missing_open_curly.carbon:[[@LINE+13]]:21: error: `interface` declarations must either end with a `;` or have a `{ ... }` block for a definition [ExpectedDeclSemiOrDefinition]
+// CHECK:STDERR: fail_missing_open_curly.carbon:[[@LINE+14]]:21: error: `interface` declarations must either end with a `;` or have a `{ ... }` block for a definition [ExpectedDeclSemiOrDefinition]
 // CHECK:STDERR: // CHECK:STDOUT:   ]
 // CHECK:STDERR:                     ^
+// CHECK:STDERR:
 // CHECK:STDOUT: - filename: fail_missing_open_curly.carbon
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
diff --git a/toolchain/parse/testdata/generics/interface/fail_self_param_syntax.carbon b/toolchain/parse/testdata/generics/interface/fail_self_param_syntax.carbon
index 49f0f76a88e1..e9809dc0887a 100644
--- a/toolchain/parse/testdata/generics/interface/fail_self_param_syntax.carbon
+++ b/toolchain/parse/testdata/generics/interface/fail_self_param_syntax.carbon
@@ -15,9 +15,10 @@ interface Foo {
   // CHECK:STDERR:
   fn Sub[me Self](b: Self) -> Self;
 
-  // CHECK:STDERR: fail_self_param_syntax.carbon:[[@LINE+3]]:10: error: expected name in binding pattern [ExpectedBindingPattern]
+  // CHECK:STDERR: fail_self_param_syntax.carbon:[[@LINE+4]]:10: error: expected name in binding pattern [ExpectedBindingPattern]
   // CHECK:STDERR:   fn Mul[Self](b: Self) -> Self;
   // CHECK:STDERR:          ^~~~
+  // CHECK:STDERR:
   fn Mul[Self](b: Self) -> Self;
 }
 
diff --git a/toolchain/parse/testdata/generics/named_constraint/fail_incomplete.carbon b/toolchain/parse/testdata/generics/named_constraint/fail_incomplete.carbon
index cd192bc8d701..d3713d331de4 100644
--- a/toolchain/parse/testdata/generics/named_constraint/fail_incomplete.carbon
+++ b/toolchain/parse/testdata/generics/named_constraint/fail_incomplete.carbon
@@ -14,9 +14,10 @@
 // CHECK:STDERR:
 constraint "Foo"
 
-// CHECK:STDERR: fail_incomplete.carbon:[[@LINE+3]]:1: error: `constraint` introducer should be followed by a name [ExpectedDeclName]
+// CHECK:STDERR: fail_incomplete.carbon:[[@LINE+4]]:1: error: `constraint` introducer should be followed by a name [ExpectedDeclName]
 // CHECK:STDERR: constraint
 // CHECK:STDERR: ^~~~~~~~~~
+// CHECK:STDERR:
 constraint
 
 // CHECK:STDOUT: - filename: fail_incomplete.carbon
diff --git a/toolchain/parse/testdata/if/fail_else_unbraced.carbon b/toolchain/parse/testdata/if/fail_else_unbraced.carbon
index e08c62a3cfcb..d3d1e746e703 100644
--- a/toolchain/parse/testdata/if/fail_else_unbraced.carbon
+++ b/toolchain/parse/testdata/if/fail_else_unbraced.carbon
@@ -27,9 +27,10 @@ fn F() {
       // CHECK:STDERR:
       d;
   else
-    // CHECK:STDERR: fail_else_unbraced.carbon:[[@LINE+3]]:5: error: expected braced code block [ExpectedCodeBlock]
+    // CHECK:STDERR: fail_else_unbraced.carbon:[[@LINE+4]]:5: error: expected braced code block [ExpectedCodeBlock]
     // CHECK:STDERR:     e;
     // CHECK:STDERR:     ^
+    // CHECK:STDERR:
     e;
   if (x) { f; }
   else if (x) { g; }
diff --git a/toolchain/parse/testdata/if/fail_errors.carbon b/toolchain/parse/testdata/if/fail_errors.carbon
index c5de9be55b7a..0d7ef8e1f227 100644
--- a/toolchain/parse/testdata/if/fail_errors.carbon
+++ b/toolchain/parse/testdata/if/fail_errors.carbon
@@ -25,13 +25,14 @@ fn F() {
   // CHECK:STDERR:
   if (b c) {}
   if (d)
-// CHECK:STDERR: fail_errors.carbon:[[@LINE+7]]:1: error: expected braced code block [ExpectedCodeBlock]
+// CHECK:STDERR: fail_errors.carbon:[[@LINE+8]]:1: error: expected braced code block [ExpectedCodeBlock]
 // CHECK:STDERR: }
 // CHECK:STDERR: ^
 // CHECK:STDERR:
-// CHECK:STDERR: fail_errors.carbon:[[@LINE+3]]:1: error: expected expression [ExpectedExpr]
+// CHECK:STDERR: fail_errors.carbon:[[@LINE+4]]:1: error: expected expression [ExpectedExpr]
 // CHECK:STDERR: }
 // CHECK:STDERR: ^
+// CHECK:STDERR:
 }
 
 // CHECK:STDOUT: - filename: fail_errors.carbon
diff --git a/toolchain/parse/testdata/if/fail_missing_cond.carbon b/toolchain/parse/testdata/if/fail_missing_cond.carbon
index d9a773601357..b2379b5428f0 100644
--- a/toolchain/parse/testdata/if/fail_missing_cond.carbon
+++ b/toolchain/parse/testdata/if/fail_missing_cond.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/if/fail_missing_cond.carbon
 
 fn F() {
-  // CHECK:STDERR: fail_missing_cond.carbon:[[@LINE+3]]:6: error: expected `(` after `if` [ExpectedParenAfter]
+  // CHECK:STDERR: fail_missing_cond.carbon:[[@LINE+4]]:6: error: expected `(` after `if` [ExpectedParenAfter]
   // CHECK:STDERR:   if {
   // CHECK:STDERR:      ^
+  // CHECK:STDERR:
   if {
   }
 }
diff --git a/toolchain/parse/testdata/if/fail_square_brackets.carbon b/toolchain/parse/testdata/if/fail_square_brackets.carbon
index 336b73779bdb..2a270e73a316 100644
--- a/toolchain/parse/testdata/if/fail_square_brackets.carbon
+++ b/toolchain/parse/testdata/if/fail_square_brackets.carbon
@@ -9,17 +9,18 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/if/fail_square_brackets.carbon
 
 fn F() {
-  // CHECK:STDERR: fail_square_brackets.carbon:[[@LINE+11]]:6: error: expected `(` after `if` [ExpectedParenAfter]
+  // CHECK:STDERR: fail_square_brackets.carbon:[[@LINE+12]]:6: error: expected `(` after `if` [ExpectedParenAfter]
   // CHECK:STDERR:   if [] {}
   // CHECK:STDERR:      ^
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_square_brackets.carbon:[[@LINE+7]]:7: error: expected expression [ExpectedExpr]
+  // CHECK:STDERR: fail_square_brackets.carbon:[[@LINE+8]]:7: error: expected expression [ExpectedExpr]
   // CHECK:STDERR:   if [] {}
   // CHECK:STDERR:       ^
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_square_brackets.carbon:[[@LINE+3]]:7: error: expected `;` in array type [ExpectedArraySemi]
+  // CHECK:STDERR: fail_square_brackets.carbon:[[@LINE+4]]:7: error: expected `;` in array type [ExpectedArraySemi]
   // CHECK:STDERR:   if [] {}
   // CHECK:STDERR:       ^
+  // CHECK:STDERR:
   if [] {}
 }
 
diff --git a/toolchain/parse/testdata/if/fail_unbraced.carbon b/toolchain/parse/testdata/if/fail_unbraced.carbon
index 4633aeaddacb..b21a4d7e7247 100644
--- a/toolchain/parse/testdata/if/fail_unbraced.carbon
+++ b/toolchain/parse/testdata/if/fail_unbraced.carbon
@@ -21,9 +21,10 @@ fn F() {
       // CHECK:STDERR:       ^~
       // CHECK:STDERR:
       if (c)
-        // CHECK:STDERR: fail_unbraced.carbon:[[@LINE+3]]:9: error: expected braced code block [ExpectedCodeBlock]
+        // CHECK:STDERR: fail_unbraced.carbon:[[@LINE+4]]:9: error: expected braced code block [ExpectedCodeBlock]
         // CHECK:STDERR:         d;
         // CHECK:STDERR:         ^
+        // CHECK:STDERR:
         d;
 }
 
diff --git a/toolchain/parse/testdata/if_expr/fail_condition_missing.carbon b/toolchain/parse/testdata/if_expr/fail_condition_missing.carbon
index 87310c8f98ae..2c3d59d64bde 100644
--- a/toolchain/parse/testdata/if_expr/fail_condition_missing.carbon
+++ b/toolchain/parse/testdata/if_expr/fail_condition_missing.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/if_expr/fail_condition_missing.carbon
 
 fn F() {
-  // CHECK:STDERR: fail_condition_missing.carbon:[[@LINE+3]]:18: error: expected expression [ExpectedExpr]
+  // CHECK:STDERR: fail_condition_missing.carbon:[[@LINE+4]]:18: error: expected expression [ExpectedExpr]
   // CHECK:STDERR:   var n: i32 = if;
   // CHECK:STDERR:                  ^
+  // CHECK:STDERR:
   var n: i32 = if;
 }
 
diff --git a/toolchain/parse/testdata/if_expr/fail_else_expr_missing.carbon b/toolchain/parse/testdata/if_expr/fail_else_expr_missing.carbon
index 0a2e726d6e3e..5e03779e7323 100644
--- a/toolchain/parse/testdata/if_expr/fail_else_expr_missing.carbon
+++ b/toolchain/parse/testdata/if_expr/fail_else_expr_missing.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/if_expr/fail_else_expr_missing.carbon
 
 fn F() {
-  // CHECK:STDERR: fail_else_expr_missing.carbon:[[@LINE+3]]:35: error: expected expression [ExpectedExpr]
+  // CHECK:STDERR: fail_else_expr_missing.carbon:[[@LINE+4]]:35: error: expected expression [ExpectedExpr]
   // CHECK:STDERR:   var n: i32 = if true then 1 else;
   // CHECK:STDERR:                                   ^
+  // CHECK:STDERR:
   var n: i32 = if true then 1 else;
 }
 
diff --git a/toolchain/parse/testdata/if_expr/fail_else_missing.carbon b/toolchain/parse/testdata/if_expr/fail_else_missing.carbon
index 4f90f70df290..cee072dd30b1 100644
--- a/toolchain/parse/testdata/if_expr/fail_else_missing.carbon
+++ b/toolchain/parse/testdata/if_expr/fail_else_missing.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/if_expr/fail_else_missing.carbon
 
 fn F() {
-  // CHECK:STDERR: fail_else_missing.carbon:[[@LINE+3]]:30: error: expected `else` after `if ... then ...` [ExpectedElseAfterIf]
+  // CHECK:STDERR: fail_else_missing.carbon:[[@LINE+4]]:30: error: expected `else` after `if ... then ...` [ExpectedElseAfterIf]
   // CHECK:STDERR:   var n: i32 = if true then 1;
   // CHECK:STDERR:                              ^
+  // CHECK:STDERR:
   var n: i32 = if true then 1;
 }
 
diff --git a/toolchain/parse/testdata/if_expr/fail_then_expr_missing.carbon b/toolchain/parse/testdata/if_expr/fail_then_expr_missing.carbon
index 35f7d3f5e2c9..6c077f77e2ec 100644
--- a/toolchain/parse/testdata/if_expr/fail_then_expr_missing.carbon
+++ b/toolchain/parse/testdata/if_expr/fail_then_expr_missing.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/if_expr/fail_then_expr_missing.carbon
 
 fn F() {
-  // CHECK:STDERR: fail_then_expr_missing.carbon:[[@LINE+3]]:28: error: expected expression [ExpectedExpr]
+  // CHECK:STDERR: fail_then_expr_missing.carbon:[[@LINE+4]]:28: error: expected expression [ExpectedExpr]
   // CHECK:STDERR:   var n: i32 = if true then;
   // CHECK:STDERR:                            ^
+  // CHECK:STDERR:
   var n: i32 = if true then;
 }
 
diff --git a/toolchain/parse/testdata/if_expr/fail_then_missing.carbon b/toolchain/parse/testdata/if_expr/fail_then_missing.carbon
index f343f0def9b1..355e41db3de4 100644
--- a/toolchain/parse/testdata/if_expr/fail_then_missing.carbon
+++ b/toolchain/parse/testdata/if_expr/fail_then_missing.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/if_expr/fail_then_missing.carbon
 
 fn F() {
-  // CHECK:STDERR: fail_then_missing.carbon:[[@LINE+3]]:23: error: expected `then` after `if` condition [ExpectedThenAfterIf]
+  // CHECK:STDERR: fail_then_missing.carbon:[[@LINE+4]]:23: error: expected `then` after `if` condition [ExpectedThenAfterIf]
   // CHECK:STDERR:   var n: i32 = if true;
   // CHECK:STDERR:                       ^
+  // CHECK:STDERR:
   var n: i32 = if true;
 }
 
diff --git a/toolchain/parse/testdata/if_expr/fail_top_level_if.carbon b/toolchain/parse/testdata/if_expr/fail_top_level_if.carbon
index cd9beb834217..49f52823761b 100644
--- a/toolchain/parse/testdata/if_expr/fail_top_level_if.carbon
+++ b/toolchain/parse/testdata/if_expr/fail_top_level_if.carbon
@@ -9,17 +9,18 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/if_expr/fail_top_level_if.carbon
 
 fn F() {
-  // CHECK:STDERR: fail_top_level_if.carbon:[[@LINE+11]]:6: error: expected `(` after `if` [ExpectedParenAfter]
+  // CHECK:STDERR: fail_top_level_if.carbon:[[@LINE+12]]:6: error: expected `(` after `if` [ExpectedParenAfter]
   // CHECK:STDERR:   if true then 1 else 2;
   // CHECK:STDERR:      ^~~~
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_top_level_if.carbon:[[@LINE+7]]:11: error: expected braced code block [ExpectedCodeBlock]
+  // CHECK:STDERR: fail_top_level_if.carbon:[[@LINE+8]]:11: error: expected braced code block [ExpectedCodeBlock]
   // CHECK:STDERR:   if true then 1 else 2;
   // CHECK:STDERR:           ^~~~
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_top_level_if.carbon:[[@LINE+3]]:11: error: expected expression [ExpectedExpr]
+  // CHECK:STDERR: fail_top_level_if.carbon:[[@LINE+4]]:11: error: expected expression [ExpectedExpr]
   // CHECK:STDERR:   if true then 1 else 2;
   // CHECK:STDERR:           ^~~~
+  // CHECK:STDERR:
   if true then 1 else 2;
 }
 
diff --git a/toolchain/parse/testdata/index/fail_empty_expr.carbon b/toolchain/parse/testdata/index/fail_empty_expr.carbon
index e1909fb92450..078aa273076e 100644
--- a/toolchain/parse/testdata/index/fail_empty_expr.carbon
+++ b/toolchain/parse/testdata/index/fail_empty_expr.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/index/fail_empty_expr.carbon
 
-// CHECK:STDERR: fail_empty_expr.carbon:[[@LINE+3]]:16: error: expected expression [ExpectedExpr]
+// CHECK:STDERR: fail_empty_expr.carbon:[[@LINE+4]]:16: error: expected expression [ExpectedExpr]
 // CHECK:STDERR: var v: i32 = t[];
 // CHECK:STDERR:                ^
+// CHECK:STDERR:
 var v: i32 = t[];
 
 // CHECK:STDOUT: - filename: fail_empty_expr.carbon
diff --git a/toolchain/parse/testdata/index/fail_malformed_expr.carbon b/toolchain/parse/testdata/index/fail_malformed_expr.carbon
index c836fba8e90d..98fd497708bb 100644
--- a/toolchain/parse/testdata/index/fail_malformed_expr.carbon
+++ b/toolchain/parse/testdata/index/fail_malformed_expr.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/index/fail_malformed_expr.carbon
 
-// CHECK:STDERR: fail_malformed_expr.carbon:[[@LINE+3]]:17: error: unexpected tokens before `]` [ExpectedCloseSymbol]
+// CHECK:STDERR: fail_malformed_expr.carbon:[[@LINE+4]]:17: error: unexpected tokens before `]` [ExpectedCloseSymbol]
 // CHECK:STDERR: var v: i32 = t[0,];
 // CHECK:STDERR:                 ^
+// CHECK:STDERR:
 var v: i32 = t[0,];
 
 // CHECK:STDOUT: - filename: fail_malformed_expr.carbon
diff --git a/toolchain/parse/testdata/let/fail_bad_name.carbon b/toolchain/parse/testdata/let/fail_bad_name.carbon
index 57c15c630624..440be4142d80 100644
--- a/toolchain/parse/testdata/let/fail_bad_name.carbon
+++ b/toolchain/parse/testdata/let/fail_bad_name.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/let/fail_bad_name.carbon
 
-// CHECK:STDERR: fail_bad_name.carbon:[[@LINE+3]]:5: error: expected name in binding pattern [ExpectedBindingPattern]
+// CHECK:STDERR: fail_bad_name.carbon:[[@LINE+4]]:5: error: expected name in binding pattern [ExpectedBindingPattern]
 // CHECK:STDERR: let ? = 4;
 // CHECK:STDERR:     ^
+// CHECK:STDERR:
 let ? = 4;
 
 // CHECK:STDOUT: - filename: fail_bad_name.carbon
diff --git a/toolchain/parse/testdata/let/fail_empty.carbon b/toolchain/parse/testdata/let/fail_empty.carbon
index 1a22b484bdfb..68a24f6842e8 100644
--- a/toolchain/parse/testdata/let/fail_empty.carbon
+++ b/toolchain/parse/testdata/let/fail_empty.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/let/fail_empty.carbon
 
-// CHECK:STDERR: fail_empty.carbon:[[@LINE+3]]:4: error: expected name in binding pattern [ExpectedBindingPattern]
+// CHECK:STDERR: fail_empty.carbon:[[@LINE+4]]:4: error: expected name in binding pattern [ExpectedBindingPattern]
 // CHECK:STDERR: let;
 // CHECK:STDERR:    ^
+// CHECK:STDERR:
 let;
 
 // CHECK:STDOUT: - filename: fail_empty.carbon
diff --git a/toolchain/parse/testdata/let/fail_missing_name.carbon b/toolchain/parse/testdata/let/fail_missing_name.carbon
index a36e9f8d9ecf..54981a6a35e5 100644
--- a/toolchain/parse/testdata/let/fail_missing_name.carbon
+++ b/toolchain/parse/testdata/let/fail_missing_name.carbon
@@ -18,9 +18,10 @@ let : i32 = 4;
 
 // --- fail_complietime_binding.carbon
 
-// CHECK:STDERR: fail_complietime_binding.carbon:[[@LINE+3]]:5: error: expected name in binding pattern [ExpectedBindingPattern]
+// CHECK:STDERR: fail_complietime_binding.carbon:[[@LINE+4]]:5: error: expected name in binding pattern [ExpectedBindingPattern]
 // CHECK:STDERR: let :! bool = true;
 // CHECK:STDERR:     ^~
+// CHECK:STDERR:
 let :! bool = true;
 
 // CHECK:STDOUT: - filename: fail_runtime_binding.carbon
diff --git a/toolchain/parse/testdata/let/fail_missing_type.carbon b/toolchain/parse/testdata/let/fail_missing_type.carbon
index 0ddc3e70de98..442d9b3c04a0 100644
--- a/toolchain/parse/testdata/let/fail_missing_type.carbon
+++ b/toolchain/parse/testdata/let/fail_missing_type.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/let/fail_missing_type.carbon
 
-// CHECK:STDERR: fail_missing_type.carbon:[[@LINE+3]]:7: error: expected `:` or `:!` in binding pattern [ExpectedBindingPattern]
+// CHECK:STDERR: fail_missing_type.carbon:[[@LINE+4]]:7: error: expected `:` or `:!` in binding pattern [ExpectedBindingPattern]
 // CHECK:STDERR: let a = 4;
 // CHECK:STDERR:       ^
+// CHECK:STDERR:
 let a = 4;
 
 // CHECK:STDOUT: - filename: fail_missing_type.carbon
diff --git a/toolchain/parse/testdata/let/fail_no_semi.carbon b/toolchain/parse/testdata/let/fail_no_semi.carbon
index 11e326392439..ecc6bd8ab564 100644
--- a/toolchain/parse/testdata/let/fail_no_semi.carbon
+++ b/toolchain/parse/testdata/let/fail_no_semi.carbon
@@ -10,13 +10,14 @@
 
 let
 
-// CHECK:STDERR: fail_no_semi.carbon:[[@LINE+16]]:21: error: expected name in binding pattern [ExpectedBindingPattern]
+// CHECK:STDERR: fail_no_semi.carbon:[[@LINE+17]]:21: error: expected name in binding pattern [ExpectedBindingPattern]
 // CHECK:STDERR: // CHECK:STDOUT:   ]
 // CHECK:STDERR:                     ^
 // CHECK:STDERR:
-// CHECK:STDERR: fail_no_semi.carbon:[[@LINE+12]]:21: error: `let` declarations must end with a `;` [ExpectedDeclSemi]
+// CHECK:STDERR: fail_no_semi.carbon:[[@LINE+13]]:21: error: `let` declarations must end with a `;` [ExpectedDeclSemi]
 // CHECK:STDERR: // CHECK:STDOUT:   ]
 // CHECK:STDERR:                     ^
+// CHECK:STDERR:
 // CHECK:STDOUT: - filename: fail_no_semi.carbon
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
diff --git a/toolchain/parse/testdata/match/fail_cases_after_default.carbon b/toolchain/parse/testdata/match/fail_cases_after_default.carbon
index 6a2608ee12e1..b445bc2822ec 100644
--- a/toolchain/parse/testdata/match/fail_cases_after_default.carbon
+++ b/toolchain/parse/testdata/match/fail_cases_after_default.carbon
@@ -22,9 +22,10 @@ fn f() -> i32 {
     // CHECK:STDERR:     ^~~~~~~
     // CHECK:STDERR:
     default => { return 3; }
-    // CHECK:STDERR: fail_cases_after_default.carbon:[[@LINE+3]]:5: error: unreachable case; `case` occurs after the `default` [UnreachableMatchCase]
+    // CHECK:STDERR: fail_cases_after_default.carbon:[[@LINE+4]]:5: error: unreachable case; `case` occurs after the `default` [UnreachableMatchCase]
     // CHECK:STDERR:     case (a: i32) if (a == 4) => { return 4; }
     // CHECK:STDERR:     ^~~~
+    // CHECK:STDERR:
     case (a: i32) if (a == 4) => { return 4; }
   }
   return 0;
diff --git a/toolchain/parse/testdata/match/fail_missing_case_arrow.carbon b/toolchain/parse/testdata/match/fail_missing_case_arrow.carbon
index 6174b2d639e6..7e7e931771c0 100644
--- a/toolchain/parse/testdata/match/fail_missing_case_arrow.carbon
+++ b/toolchain/parse/testdata/match/fail_missing_case_arrow.carbon
@@ -15,9 +15,10 @@ fn f() -> i32 {
     // CHECK:STDERR:                 ^
     // CHECK:STDERR:
     case x: i32 { return 2; }
-    // CHECK:STDERR: fail_missing_case_arrow.carbon:[[@LINE+3]]:29: error: expected `=>` introducing statement block [ExpectedMatchCaseArrow]
+    // CHECK:STDERR: fail_missing_case_arrow.carbon:[[@LINE+4]]:29: error: expected `=>` introducing statement block [ExpectedMatchCaseArrow]
     // CHECK:STDERR:     case x: i32 if (x == 3) { return 3; }
     // CHECK:STDERR:                             ^
+    // CHECK:STDERR:
     case x: i32 if (x == 3) { return 3; }
   }
   return 0;
diff --git a/toolchain/parse/testdata/match/fail_missing_case_pattern.carbon b/toolchain/parse/testdata/match/fail_missing_case_pattern.carbon
index d3334027b73a..754b9ddb42a7 100644
--- a/toolchain/parse/testdata/match/fail_missing_case_pattern.carbon
+++ b/toolchain/parse/testdata/match/fail_missing_case_pattern.carbon
@@ -10,9 +10,10 @@
 
 fn f() -> i32 {
   match (3) {
-    // CHECK:STDERR: fail_missing_case_pattern.carbon:[[@LINE+3]]:10: error: expected name in binding pattern [ExpectedBindingPattern]
+    // CHECK:STDERR: fail_missing_case_pattern.carbon:[[@LINE+4]]:10: error: expected name in binding pattern [ExpectedBindingPattern]
     // CHECK:STDERR:     case => { return 2; }
     // CHECK:STDERR:          ^~
+    // CHECK:STDERR:
     case => { return 2; }
   }
   return 0;
diff --git a/toolchain/parse/testdata/match/fail_missing_case_statements_block.carbon b/toolchain/parse/testdata/match/fail_missing_case_statements_block.carbon
index b42b414513b0..f61caca4a2c7 100644
--- a/toolchain/parse/testdata/match/fail_missing_case_statements_block.carbon
+++ b/toolchain/parse/testdata/match/fail_missing_case_statements_block.carbon
@@ -11,9 +11,10 @@
 fn f() -> i32 {
   match (3) {
     case x: i32 =>
-    // CHECK:STDERR: fail_missing_case_statements_block.carbon:[[@LINE+3]]:5: error: expected `{` after `=>` [ExpectedMatchCaseBlock]
+    // CHECK:STDERR: fail_missing_case_statements_block.carbon:[[@LINE+4]]:5: error: expected `{` after `=>` [ExpectedMatchCaseBlock]
     // CHECK:STDERR:     default => { return 3; }
     // CHECK:STDERR:     ^~~~~~~
+    // CHECK:STDERR:
     default => { return 3; }
   }
   return 0;
diff --git a/toolchain/parse/testdata/match/fail_missing_cases.carbon b/toolchain/parse/testdata/match/fail_missing_cases.carbon
index aeb9f1a4b77b..65439a0e1233 100644
--- a/toolchain/parse/testdata/match/fail_missing_cases.carbon
+++ b/toolchain/parse/testdata/match/fail_missing_cases.carbon
@@ -10,9 +10,10 @@
 
 
 fn f() -> i32 {
-  // CHECK:STDERR: fail_missing_cases.carbon:[[@LINE+3]]:14: error: expected cases [ExpectedMatchCases]
+  // CHECK:STDERR: fail_missing_cases.carbon:[[@LINE+4]]:14: error: expected cases [ExpectedMatchCases]
   // CHECK:STDERR:   match (3) {}
   // CHECK:STDERR:              ^
+  // CHECK:STDERR:
   match (3) {}
   return 0;
 }
diff --git a/toolchain/parse/testdata/match/fail_missing_cases_block.carbon b/toolchain/parse/testdata/match/fail_missing_cases_block.carbon
index 8747c189be6f..ed93173a2d16 100644
--- a/toolchain/parse/testdata/match/fail_missing_cases_block.carbon
+++ b/toolchain/parse/testdata/match/fail_missing_cases_block.carbon
@@ -10,9 +10,10 @@
 
 fn f() -> i32 {
   match (1)
-  // CHECK:STDERR: fail_missing_cases_block.carbon:[[@LINE+3]]:3: error: expected `{` starting block with cases [ExpectedMatchCasesBlock]
+  // CHECK:STDERR: fail_missing_cases_block.carbon:[[@LINE+4]]:3: error: expected `{` starting block with cases [ExpectedMatchCasesBlock]
   // CHECK:STDERR:   return 0;
   // CHECK:STDERR:   ^~~~~~
+  // CHECK:STDERR:
   return 0;
 }
 
diff --git a/toolchain/parse/testdata/match/fail_missing_default_arrow.carbon b/toolchain/parse/testdata/match/fail_missing_default_arrow.carbon
index baca9f9374ec..c36dc731d80e 100644
--- a/toolchain/parse/testdata/match/fail_missing_default_arrow.carbon
+++ b/toolchain/parse/testdata/match/fail_missing_default_arrow.carbon
@@ -10,9 +10,10 @@
 
 fn f() -> i32 {
   match (3) {
-    // CHECK:STDERR: fail_missing_default_arrow.carbon:[[@LINE+3]]:13: error: expected `=>` introducing statement block [ExpectedMatchCaseArrow]
+    // CHECK:STDERR: fail_missing_default_arrow.carbon:[[@LINE+4]]:13: error: expected `=>` introducing statement block [ExpectedMatchCaseArrow]
     // CHECK:STDERR:     default { return 1; }
     // CHECK:STDERR:             ^
+    // CHECK:STDERR:
     default { return 1; }
   }
   return 0;
diff --git a/toolchain/parse/testdata/match/fail_missing_default_statements_block.carbon b/toolchain/parse/testdata/match/fail_missing_default_statements_block.carbon
index 0b89e5865fcc..b75e58f2d583 100644
--- a/toolchain/parse/testdata/match/fail_missing_default_statements_block.carbon
+++ b/toolchain/parse/testdata/match/fail_missing_default_statements_block.carbon
@@ -11,9 +11,10 @@
 fn f() -> i32 {
   match (3) {
     default =>
-  // CHECK:STDERR: fail_missing_default_statements_block.carbon:[[@LINE+3]]:3: error: expected `{` after `=>` [ExpectedMatchCaseBlock]
+  // CHECK:STDERR: fail_missing_default_statements_block.carbon:[[@LINE+4]]:3: error: expected `{` after `=>` [ExpectedMatchCaseBlock]
   // CHECK:STDERR:   }
   // CHECK:STDERR:   ^
+  // CHECK:STDERR:
   }
   return 0;
 }
diff --git a/toolchain/parse/testdata/match/fail_missing_guard_close_paren.carbon b/toolchain/parse/testdata/match/fail_missing_guard_close_paren.carbon
index bd825b501626..6ffedb2f0d14 100644
--- a/toolchain/parse/testdata/match/fail_missing_guard_close_paren.carbon
+++ b/toolchain/parse/testdata/match/fail_missing_guard_close_paren.carbon
@@ -10,13 +10,14 @@
 
 fn f() -> i32 {
   match (true) {
-    // CHECK:STDERR: fail_missing_guard_close_paren.carbon:[[@LINE+7]]:21: error: opening symbol without a corresponding closing symbol [UnmatchedOpening]
+    // CHECK:STDERR: fail_missing_guard_close_paren.carbon:[[@LINE+8]]:21: error: opening symbol without a corresponding closing symbol [UnmatchedOpening]
     // CHECK:STDERR:     case x: bool if (false => { return 1; }
     // CHECK:STDERR:                     ^
     // CHECK:STDERR:
-    // CHECK:STDERR: fail_missing_guard_close_paren.carbon:[[@LINE+3]]:28: error: TODO: improve match parsing [MatchParseTODO]
+    // CHECK:STDERR: fail_missing_guard_close_paren.carbon:[[@LINE+4]]:28: error: TODO: improve match parsing [MatchParseTODO]
     // CHECK:STDERR:     case x: bool if (false => { return 1; }
     // CHECK:STDERR:                            ^~
+    // CHECK:STDERR:
     case x: bool if (false => { return 1; }
   }
   return 0;
diff --git a/toolchain/parse/testdata/match/fail_missing_guard_open_paren.carbon b/toolchain/parse/testdata/match/fail_missing_guard_open_paren.carbon
index a6cb6cd1e497..4d5860adf4f0 100644
--- a/toolchain/parse/testdata/match/fail_missing_guard_open_paren.carbon
+++ b/toolchain/parse/testdata/match/fail_missing_guard_open_paren.carbon
@@ -10,13 +10,14 @@
 
 fn f() -> i32 {
   match (true) {
-    // CHECK:STDERR: fail_missing_guard_open_paren.carbon:[[@LINE+7]]:21: error: TODO: improve match parsing [MatchParseTODO]
+    // CHECK:STDERR: fail_missing_guard_open_paren.carbon:[[@LINE+8]]:21: error: TODO: improve match parsing [MatchParseTODO]
     // CHECK:STDERR:     case x: bool if false) => { return 1; }
     // CHECK:STDERR:                     ^~~~~
     // CHECK:STDERR:
-    // CHECK:STDERR: fail_missing_guard_open_paren.carbon:[[@LINE+3]]:26: error: closing symbol without a corresponding opening symbol [UnmatchedClosing]
+    // CHECK:STDERR: fail_missing_guard_open_paren.carbon:[[@LINE+4]]:26: error: closing symbol without a corresponding opening symbol [UnmatchedClosing]
     // CHECK:STDERR:     case x: bool if false) => { return 1; }
     // CHECK:STDERR:                          ^
+    // CHECK:STDERR:
     case x: bool if false) => { return 1; }
   }
   return 0;
diff --git a/toolchain/parse/testdata/match/fail_missing_matched_expr.carbon b/toolchain/parse/testdata/match/fail_missing_matched_expr.carbon
index 36e72b668dcb..579c7a7ca097 100644
--- a/toolchain/parse/testdata/match/fail_missing_matched_expr.carbon
+++ b/toolchain/parse/testdata/match/fail_missing_matched_expr.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/match/fail_missing_matched_expr.carbon
 
 fn f() -> i32 {
-  // CHECK:STDERR: fail_missing_matched_expr.carbon:[[@LINE+3]]:9: error: expected `(` after `match` [ExpectedParenAfter]
+  // CHECK:STDERR: fail_missing_matched_expr.carbon:[[@LINE+4]]:9: error: expected `(` after `match` [ExpectedParenAfter]
   // CHECK:STDERR:   match {
   // CHECK:STDERR:         ^
+  // CHECK:STDERR:
   match {
     default => { return 1; }
   }
diff --git a/toolchain/parse/testdata/match/fail_unexpected_tokens_in_cases_block.carbon b/toolchain/parse/testdata/match/fail_unexpected_tokens_in_cases_block.carbon
index 48092b57db80..5a223b88248f 100644
--- a/toolchain/parse/testdata/match/fail_unexpected_tokens_in_cases_block.carbon
+++ b/toolchain/parse/testdata/match/fail_unexpected_tokens_in_cases_block.carbon
@@ -43,9 +43,10 @@ fn f() -> i32 {
     // CHECK:STDERR:     ^~~~~~
     // CHECK:STDERR:
     return 1;
-    // CHECK:STDERR: fail_unexpected_tokens_in_cases_block.carbon:[[@LINE+3]]:5: error: unexpected `(`; expected `case`, `default` or `}` [UnexpectedTokenInMatchCasesBlock]
+    // CHECK:STDERR: fail_unexpected_tokens_in_cases_block.carbon:[[@LINE+4]]:5: error: unexpected `(`; expected `case`, `default` or `}` [UnexpectedTokenInMatchCasesBlock]
     // CHECK:STDERR:     ((), (), ())
     // CHECK:STDERR:     ^
+    // CHECK:STDERR:
     ((), (), ())
   }
   return 0;
diff --git a/toolchain/parse/testdata/member_access/fail_keyword.carbon b/toolchain/parse/testdata/member_access/fail_keyword.carbon
index b63e202d603b..63b1b43db45b 100644
--- a/toolchain/parse/testdata/member_access/fail_keyword.carbon
+++ b/toolchain/parse/testdata/member_access/fail_keyword.carbon
@@ -34,9 +34,10 @@ fn F() {
   // CHECK:STDERR:      ^~~~
   // CHECK:STDERR:
   p->Self;
-  // CHECK:STDERR: fail_keyword.carbon:[[@LINE+3]]:6: error: expected identifier after `->` [ExpectedIdentifierAfterPeriodOrArrow]
+  // CHECK:STDERR: fail_keyword.carbon:[[@LINE+4]]:6: error: expected identifier after `->` [ExpectedIdentifierAfterPeriodOrArrow]
   // CHECK:STDERR:   p->while;
   // CHECK:STDERR:      ^~~~~
+  // CHECK:STDERR:
   p->while;
 }
 
diff --git a/toolchain/parse/testdata/namespace/fail_arrow.carbon b/toolchain/parse/testdata/namespace/fail_arrow.carbon
index a3aff1f15877..af859372653c 100644
--- a/toolchain/parse/testdata/namespace/fail_arrow.carbon
+++ b/toolchain/parse/testdata/namespace/fail_arrow.carbon
@@ -10,9 +10,10 @@
 
 namespace Foo;
 
-// CHECK:STDERR: fail_arrow.carbon:[[@LINE+3]]:10: error: `class` declarations must either end with a `;` or have a `{ ... }` block for a definition [ExpectedDeclSemiOrDefinition]
+// CHECK:STDERR: fail_arrow.carbon:[[@LINE+4]]:10: error: `class` declarations must either end with a `;` or have a `{ ... }` block for a definition [ExpectedDeclSemiOrDefinition]
 // CHECK:STDERR: class Foo->Bar {}
 // CHECK:STDERR:          ^~
+// CHECK:STDERR:
 class Foo->Bar {}
 
 // CHECK:STDOUT: - filename: fail_arrow.carbon
diff --git a/toolchain/parse/testdata/namespace/fail_incomplete.carbon b/toolchain/parse/testdata/namespace/fail_incomplete.carbon
index c7e8061c386a..3fc65854e5e3 100644
--- a/toolchain/parse/testdata/namespace/fail_incomplete.carbon
+++ b/toolchain/parse/testdata/namespace/fail_incomplete.carbon
@@ -38,9 +38,10 @@ namespace bool
 // CHECK:STDERR:
 namespace namespace namespace namespace namespace
 
-// CHECK:STDERR: fail_incomplete.carbon:[[@LINE+3]]:1: error: `namespace` introducer should be followed by a name [ExpectedDeclName]
+// CHECK:STDERR: fail_incomplete.carbon:[[@LINE+4]]:1: error: `namespace` introducer should be followed by a name [ExpectedDeclName]
 // CHECK:STDERR: namespace
 // CHECK:STDERR: ^~~~~~~~~
+// CHECK:STDERR:
 namespace
 
 // CHECK:STDOUT: - filename: fail_incomplete.carbon
diff --git a/toolchain/parse/testdata/namespace/fail_incomplete_name.carbon b/toolchain/parse/testdata/namespace/fail_incomplete_name.carbon
index 3452e3b82964..bb1be72e9a3b 100644
--- a/toolchain/parse/testdata/namespace/fail_incomplete_name.carbon
+++ b/toolchain/parse/testdata/namespace/fail_incomplete_name.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/namespace/fail_incomplete_name.carbon
 
-// CHECK:STDERR: fail_incomplete_name.carbon:[[@LINE+3]]:15: error: `.` should be followed by a name [ExpectedDeclNameAfterPeriod]
+// CHECK:STDERR: fail_incomplete_name.carbon:[[@LINE+4]]:15: error: `.` should be followed by a name [ExpectedDeclNameAfterPeriod]
 // CHECK:STDERR: namespace Foo.;
 // CHECK:STDERR:               ^
+// CHECK:STDERR:
 namespace Foo.;
 
 // CHECK:STDOUT: - filename: fail_incomplete_name.carbon
diff --git a/toolchain/parse/testdata/namespace/fail_modifiers.carbon b/toolchain/parse/testdata/namespace/fail_modifiers.carbon
index bf98b7cbb16a..dbb81cd95ceb 100644
--- a/toolchain/parse/testdata/namespace/fail_modifiers.carbon
+++ b/toolchain/parse/testdata/namespace/fail_modifiers.carbon
@@ -10,13 +10,14 @@
 
 virtual namespace B
 
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+7]]:1: error: `namespace` declarations must end with a `;` [ExpectedDeclSemi]
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+8]]:1: error: `namespace` declarations must end with a `;` [ExpectedDeclSemi]
 // CHECK:STDERR: impl namespace
 // CHECK:STDERR: ^~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+3]]:6: error: `namespace` introducer should be followed by a name [ExpectedDeclName]
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+4]]:6: error: `namespace` introducer should be followed by a name [ExpectedDeclName]
 // CHECK:STDERR: impl namespace
 // CHECK:STDERR:      ^~~~~~~~~
+// CHECK:STDERR:
 impl namespace
 
 // CHECK:STDOUT: - filename: fail_modifiers.carbon
diff --git a/toolchain/parse/testdata/namespace/fail_no_name.carbon b/toolchain/parse/testdata/namespace/fail_no_name.carbon
index bc83b0649962..53cd52a63818 100644
--- a/toolchain/parse/testdata/namespace/fail_no_name.carbon
+++ b/toolchain/parse/testdata/namespace/fail_no_name.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/namespace/fail_no_name.carbon
 
-// CHECK:STDERR: fail_no_name.carbon:[[@LINE+3]]:10: error: `namespace` introducer should be followed by a name [ExpectedDeclName]
+// CHECK:STDERR: fail_no_name.carbon:[[@LINE+4]]:10: error: `namespace` introducer should be followed by a name [ExpectedDeclName]
 // CHECK:STDERR: namespace;
 // CHECK:STDERR:          ^
+// CHECK:STDERR:
 namespace;
 
 // CHECK:STDOUT: - filename: fail_no_name.carbon
diff --git a/toolchain/parse/testdata/operators/fail_chained_assign.carbon b/toolchain/parse/testdata/operators/fail_chained_assign.carbon
index 337c13bae94f..686610010b1d 100644
--- a/toolchain/parse/testdata/operators/fail_chained_assign.carbon
+++ b/toolchain/parse/testdata/operators/fail_chained_assign.carbon
@@ -13,9 +13,10 @@ fn F() {
   var b: i32;
 
   // TODO: Produce a custom diagnostic for this.
-  // CHECK:STDERR: fail_chained_assign.carbon:[[@LINE+3]]:9: error: operator `=` can only be used as a complete statement [StatementOperatorAsSubExpr]
+  // CHECK:STDERR: fail_chained_assign.carbon:[[@LINE+4]]:9: error: operator `=` can only be used as a complete statement [StatementOperatorAsSubExpr]
   // CHECK:STDERR:   a = b = 1;
   // CHECK:STDERR:         ^
+  // CHECK:STDERR:
   a = b = 1;
 }
 
diff --git a/toolchain/parse/testdata/operators/fail_infix_uneven_space_after.carbon b/toolchain/parse/testdata/operators/fail_infix_uneven_space_after.carbon
index 5cb2b278ea2c..598d4baa2cff 100644
--- a/toolchain/parse/testdata/operators/fail_infix_uneven_space_after.carbon
+++ b/toolchain/parse/testdata/operators/fail_infix_uneven_space_after.carbon
@@ -10,9 +10,10 @@
 
 // TODO: We could figure out that this first Failed example is infix
 // with one-token lookahead.
-// CHECK:STDERR: fail_infix_uneven_space_after.carbon:[[@LINE+3]]:16: error: `var` declarations must end with a `;` [ExpectedDeclSemi]
+// CHECK:STDERR: fail_infix_uneven_space_after.carbon:[[@LINE+4]]:16: error: `var` declarations must end with a `;` [ExpectedDeclSemi]
 // CHECK:STDERR: var n: i8 = n* n;
 // CHECK:STDERR:                ^
+// CHECK:STDERR:
 var n: i8 = n* n;
 
 // CHECK:STDOUT: - filename: fail_infix_uneven_space_after.carbon
diff --git a/toolchain/parse/testdata/operators/fail_infix_uneven_space_before.carbon b/toolchain/parse/testdata/operators/fail_infix_uneven_space_before.carbon
index 669bead76cf1..f9f9c47e5209 100644
--- a/toolchain/parse/testdata/operators/fail_infix_uneven_space_before.carbon
+++ b/toolchain/parse/testdata/operators/fail_infix_uneven_space_before.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/operators/fail_infix_uneven_space_before.carbon
 
-// CHECK:STDERR: fail_infix_uneven_space_before.carbon:[[@LINE+3]]:15: error: whitespace missing after binary operator [BinaryOperatorRequiresWhitespace]
+// CHECK:STDERR: fail_infix_uneven_space_before.carbon:[[@LINE+4]]:15: error: whitespace missing after binary operator [BinaryOperatorRequiresWhitespace]
 // CHECK:STDERR: var n: i8 = n *n;
 // CHECK:STDERR:               ^
+// CHECK:STDERR:
 var n: i8 = n *n;
 
 // CHECK:STDOUT: - filename: fail_infix_uneven_space_before.carbon
diff --git a/toolchain/parse/testdata/operators/fail_invalid_infix.carbon b/toolchain/parse/testdata/operators/fail_invalid_infix.carbon
index 942eda0ed7c3..95dde4372c65 100644
--- a/toolchain/parse/testdata/operators/fail_invalid_infix.carbon
+++ b/toolchain/parse/testdata/operators/fail_invalid_infix.carbon
@@ -18,13 +18,14 @@ var a: i32 = n == ;
 // CHECK:STDERR:              ^~
 // CHECK:STDERR:
 var b: i32 = == n;
-// CHECK:STDERR: fail_invalid_infix.carbon:[[@LINE+7]]:14: error: expected expression [ExpectedExpr]
+// CHECK:STDERR: fail_invalid_infix.carbon:[[@LINE+8]]:14: error: expected expression [ExpectedExpr]
 // CHECK:STDERR: var c: i32 = == ;
 // CHECK:STDERR:              ^~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_invalid_infix.carbon:[[@LINE+3]]:17: error: expected expression [ExpectedExpr]
+// CHECK:STDERR: fail_invalid_infix.carbon:[[@LINE+4]]:17: error: expected expression [ExpectedExpr]
 // CHECK:STDERR: var c: i32 = == ;
 // CHECK:STDERR:                 ^
+// CHECK:STDERR:
 var c: i32 = == ;
 
 // CHECK:STDOUT: - filename: fail_invalid_infix.carbon
diff --git a/toolchain/parse/testdata/operators/fail_postfix_space.carbon b/toolchain/parse/testdata/operators/fail_postfix_space.carbon
index 71046080d7bd..f72e3cd98bed 100644
--- a/toolchain/parse/testdata/operators/fail_postfix_space.carbon
+++ b/toolchain/parse/testdata/operators/fail_postfix_space.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/operators/fail_postfix_space.carbon
 
-// CHECK:STDERR: fail_postfix_space.carbon:[[@LINE+3]]:18: error: whitespace is not allowed before this unary operator [UnaryOperatorHasWhitespace]
+// CHECK:STDERR: fail_postfix_space.carbon:[[@LINE+4]]:18: error: whitespace is not allowed before this unary operator [UnaryOperatorHasWhitespace]
 // CHECK:STDERR: var v: type = i8 *;
 // CHECK:STDERR:                  ^
+// CHECK:STDERR:
 var v: type = i8 *;
 
 // CHECK:STDOUT: - filename: fail_postfix_space.carbon
diff --git a/toolchain/parse/testdata/operators/fail_postfix_space_before_comma.carbon b/toolchain/parse/testdata/operators/fail_postfix_space_before_comma.carbon
index 030843046628..4f1335dd223c 100644
--- a/toolchain/parse/testdata/operators/fail_postfix_space_before_comma.carbon
+++ b/toolchain/parse/testdata/operators/fail_postfix_space_before_comma.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/operators/fail_postfix_space_before_comma.carbon
 
-// CHECK:STDERR: fail_postfix_space_before_comma.carbon:[[@LINE+3]]:18: error: whitespace is not allowed before this unary operator [UnaryOperatorHasWhitespace]
+// CHECK:STDERR: fail_postfix_space_before_comma.carbon:[[@LINE+4]]:18: error: whitespace is not allowed before this unary operator [UnaryOperatorHasWhitespace]
 // CHECK:STDERR: var n: i8 = F(i8 *, 0);
 // CHECK:STDERR:                  ^
+// CHECK:STDERR:
 var n: i8 = F(i8 *, 0);
 
 // CHECK:STDOUT: - filename: fail_postfix_space_before_comma.carbon
diff --git a/toolchain/parse/testdata/operators/fail_postfix_space_in_call.carbon b/toolchain/parse/testdata/operators/fail_postfix_space_in_call.carbon
index 5a7c5f92ca43..55795ed4037a 100644
--- a/toolchain/parse/testdata/operators/fail_postfix_space_in_call.carbon
+++ b/toolchain/parse/testdata/operators/fail_postfix_space_in_call.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/operators/fail_postfix_space_in_call.carbon
 
-// CHECK:STDERR: fail_postfix_space_in_call.carbon:[[@LINE+3]]:18: error: whitespace is not allowed before this unary operator [UnaryOperatorHasWhitespace]
+// CHECK:STDERR: fail_postfix_space_in_call.carbon:[[@LINE+4]]:18: error: whitespace is not allowed before this unary operator [UnaryOperatorHasWhitespace]
 // CHECK:STDERR: var n: i8 = F(i8 *);
 // CHECK:STDERR:                  ^
+// CHECK:STDERR:
 var n: i8 = F(i8 *);
 
 // CHECK:STDOUT: - filename: fail_postfix_space_in_call.carbon
diff --git a/toolchain/parse/testdata/operators/fail_postfix_space_surrounding.carbon b/toolchain/parse/testdata/operators/fail_postfix_space_surrounding.carbon
index bc13043beac7..3aef579cc28b 100644
--- a/toolchain/parse/testdata/operators/fail_postfix_space_surrounding.carbon
+++ b/toolchain/parse/testdata/operators/fail_postfix_space_surrounding.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/operators/fail_postfix_space_surrounding.carbon
 
-// CHECK:STDERR: fail_postfix_space_surrounding.carbon:[[@LINE+3]]:18: error: whitespace is not allowed before this unary operator [UnaryOperatorHasWhitespace]
+// CHECK:STDERR: fail_postfix_space_surrounding.carbon:[[@LINE+4]]:18: error: whitespace is not allowed before this unary operator [UnaryOperatorHasWhitespace]
 // CHECK:STDERR: var v: type = i8 * ;
 // CHECK:STDERR:                  ^
+// CHECK:STDERR:
 var v: type = i8 * ;
 
 // CHECK:STDOUT: - filename: fail_postfix_space_surrounding.carbon
diff --git a/toolchain/parse/testdata/operators/fail_postincrement.carbon b/toolchain/parse/testdata/operators/fail_postincrement.carbon
index 5875fe00c30f..6306cb2e6a2a 100644
--- a/toolchain/parse/testdata/operators/fail_postincrement.carbon
+++ b/toolchain/parse/testdata/operators/fail_postincrement.carbon
@@ -16,9 +16,10 @@ fn F() {
   // CHECK:STDERR:    ^~
   // CHECK:STDERR:
   n++;
-  // CHECK:STDERR: fail_postincrement.carbon:[[@LINE+3]]:4: error: expected `;` after expression statement [ExpectedExprSemi]
+  // CHECK:STDERR: fail_postincrement.carbon:[[@LINE+4]]:4: error: expected `;` after expression statement [ExpectedExprSemi]
   // CHECK:STDERR:   n--;
   // CHECK:STDERR:    ^~
+  // CHECK:STDERR:
   n--;
 }
 
diff --git a/toolchain/parse/testdata/operators/fail_precedence_and_or.carbon b/toolchain/parse/testdata/operators/fail_precedence_and_or.carbon
index 2c4224797e4c..a783c3566eda 100644
--- a/toolchain/parse/testdata/operators/fail_precedence_and_or.carbon
+++ b/toolchain/parse/testdata/operators/fail_precedence_and_or.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/operators/fail_precedence_and_or.carbon
 
 fn F() {
-  // CHECK:STDERR: fail_precedence_and_or.carbon:[[@LINE+3]]:11: error: parentheses are required to disambiguate operator precedence [OperatorRequiresParentheses]
+  // CHECK:STDERR: fail_precedence_and_or.carbon:[[@LINE+4]]:11: error: parentheses are required to disambiguate operator precedence [OperatorRequiresParentheses]
   // CHECK:STDERR:   a and b or c;
   // CHECK:STDERR:           ^~
+  // CHECK:STDERR:
   a and b or c;
 }
 
diff --git a/toolchain/parse/testdata/operators/fail_precedence_as.carbon b/toolchain/parse/testdata/operators/fail_precedence_as.carbon
index 3abb252b912e..7f3ca4ab5f05 100644
--- a/toolchain/parse/testdata/operators/fail_precedence_as.carbon
+++ b/toolchain/parse/testdata/operators/fail_precedence_as.carbon
@@ -46,9 +46,10 @@ fn F(n: i32) {
   // CHECK:STDERR:            ^~
   // CHECK:STDERR:
   6 as i32 == 7;
-  // CHECK:STDERR: fail_precedence_as.carbon:[[@LINE+3]]:10: error: parentheses are required to disambiguate operator precedence [OperatorRequiresParentheses]
+  // CHECK:STDERR: fail_precedence_as.carbon:[[@LINE+4]]:10: error: parentheses are required to disambiguate operator precedence [OperatorRequiresParentheses]
   // CHECK:STDERR:   8 <= 9 as i32;
   // CHECK:STDERR:          ^~
+  // CHECK:STDERR:
   8 <= 9 as i32;
 }
 
diff --git a/toolchain/parse/testdata/operators/fail_precedence_assign.carbon b/toolchain/parse/testdata/operators/fail_precedence_assign.carbon
index d73dd45b0995..c4bf63f66f86 100644
--- a/toolchain/parse/testdata/operators/fail_precedence_assign.carbon
+++ b/toolchain/parse/testdata/operators/fail_precedence_assign.carbon
@@ -31,9 +31,10 @@ fn F() {
   // CHECK:STDERR:       ^~
   // CHECK:STDERR:
   a + ++a;
-  // CHECK:STDERR: fail_precedence_assign.carbon:[[@LINE+3]]:5: error: parentheses are required around this unary `if` operator [UnaryOperatorRequiresParentheses]
+  // CHECK:STDERR: fail_precedence_assign.carbon:[[@LINE+4]]:5: error: parentheses are required around this unary `if` operator [UnaryOperatorRequiresParentheses]
   // CHECK:STDERR:   ++if c then a else b;
   // CHECK:STDERR:     ^~
+  // CHECK:STDERR:
   ++if c then a else b;
 }
 
diff --git a/toolchain/parse/testdata/operators/fail_precedence_or_and.carbon b/toolchain/parse/testdata/operators/fail_precedence_or_and.carbon
index 095319edadfc..1667de02841f 100644
--- a/toolchain/parse/testdata/operators/fail_precedence_or_and.carbon
+++ b/toolchain/parse/testdata/operators/fail_precedence_or_and.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/operators/fail_precedence_or_and.carbon
 
 fn F() {
-  // CHECK:STDERR: fail_precedence_or_and.carbon:[[@LINE+3]]:10: error: parentheses are required to disambiguate operator precedence [OperatorRequiresParentheses]
+  // CHECK:STDERR: fail_precedence_or_and.carbon:[[@LINE+4]]:10: error: parentheses are required to disambiguate operator precedence [OperatorRequiresParentheses]
   // CHECK:STDERR:   a or b and c;
   // CHECK:STDERR:          ^~~
+  // CHECK:STDERR:
   a or b and c;
 }
 
diff --git a/toolchain/parse/testdata/operators/fail_precedence_where.carbon b/toolchain/parse/testdata/operators/fail_precedence_where.carbon
index 2afd40072688..8c6cffe14606 100644
--- a/toolchain/parse/testdata/operators/fail_precedence_where.carbon
+++ b/toolchain/parse/testdata/operators/fail_precedence_where.carbon
@@ -91,9 +91,10 @@ fn AsInArgument() {
 // --- fail_greater_in_argument.carbon
 
 fn GreaterInArgument() {
-  // CHECK:STDERR: fail_greater_in_argument.carbon:[[@LINE+3]]:15: error: requirement should use `impls`, `=`, or `==` operator [ExpectedRequirementOperator]
+  // CHECK:STDERR: fail_greater_in_argument.carbon:[[@LINE+4]]:15: error: requirement should use `impls`, `=`, or `==` operator [ExpectedRequirementOperator]
   // CHECK:STDERR:   Q where .AA > .BB impls CC;
   // CHECK:STDERR:               ^
+  // CHECK:STDERR:
   Q where .AA > .BB impls CC;
 }
 
diff --git a/toolchain/parse/testdata/operators/fail_prefix_repeat.carbon b/toolchain/parse/testdata/operators/fail_prefix_repeat.carbon
index 653dc79f3cbf..4e5f09b5f623 100644
--- a/toolchain/parse/testdata/operators/fail_prefix_repeat.carbon
+++ b/toolchain/parse/testdata/operators/fail_prefix_repeat.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/operators/fail_prefix_repeat.carbon
 
-// CHECK:STDERR: fail_prefix_repeat.carbon:[[@LINE+3]]:17: error: parentheses are required around this unary `const` operator [UnaryOperatorRequiresParentheses]
+// CHECK:STDERR: fail_prefix_repeat.carbon:[[@LINE+4]]:17: error: parentheses are required around this unary `const` operator [UnaryOperatorRequiresParentheses]
 // CHECK:STDERR: fn F() -> const const i32* {
 // CHECK:STDERR:                 ^~~~~
+// CHECK:STDERR:
 fn F() -> const const i32* {
 }
 
diff --git a/toolchain/parse/testdata/operators/fail_prefix_space.carbon b/toolchain/parse/testdata/operators/fail_prefix_space.carbon
index e3a0a5a67b08..df51e4b3c0c2 100644
--- a/toolchain/parse/testdata/operators/fail_prefix_space.carbon
+++ b/toolchain/parse/testdata/operators/fail_prefix_space.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/operators/fail_prefix_space.carbon
 
-// CHECK:STDERR: fail_prefix_space.carbon:[[@LINE+3]]:13: error: whitespace is not allowed after this unary operator [UnaryOperatorHasWhitespace]
+// CHECK:STDERR: fail_prefix_space.carbon:[[@LINE+4]]:13: error: whitespace is not allowed after this unary operator [UnaryOperatorHasWhitespace]
 // CHECK:STDERR: var n: i8 = - n;
 // CHECK:STDERR:             ^
+// CHECK:STDERR:
 var n: i8 = - n;
 
 // CHECK:STDOUT: - filename: fail_prefix_space.carbon
diff --git a/toolchain/parse/testdata/operators/fail_prefix_uneven_space_with_assign.carbon b/toolchain/parse/testdata/operators/fail_prefix_uneven_space_with_assign.carbon
index 7076c713174f..c1cbd92c8d95 100644
--- a/toolchain/parse/testdata/operators/fail_prefix_uneven_space_with_assign.carbon
+++ b/toolchain/parse/testdata/operators/fail_prefix_uneven_space_with_assign.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/operators/fail_prefix_uneven_space_with_assign.carbon
 
-// CHECK:STDERR: fail_prefix_uneven_space_with_assign.carbon:[[@LINE+3]]:12: error: whitespace is not allowed after this unary operator [UnaryOperatorHasWhitespace]
+// CHECK:STDERR: fail_prefix_uneven_space_with_assign.carbon:[[@LINE+4]]:12: error: whitespace is not allowed after this unary operator [UnaryOperatorHasWhitespace]
 // CHECK:STDERR: var n: i8 =- n;
 // CHECK:STDERR:            ^
+// CHECK:STDERR:
 var n: i8 =- n;
 
 // CHECK:STDOUT: - filename: fail_prefix_uneven_space_with_assign.carbon
diff --git a/toolchain/parse/testdata/operators/fail_star_minus.carbon b/toolchain/parse/testdata/operators/fail_star_minus.carbon
index 86af91da378c..32f9fbe0f3ce 100644
--- a/toolchain/parse/testdata/operators/fail_star_minus.carbon
+++ b/toolchain/parse/testdata/operators/fail_star_minus.carbon
@@ -13,9 +13,10 @@
 // available because it has already accepted that first part of the expression,
 // so it is recovering by using the second option, but the diagnostic should
 // ideally offer (or consider) both fixes as alternatives.
-// CHECK:STDERR: fail_star_minus.carbon:[[@LINE+3]]:16: error: whitespace missing after binary operator [BinaryOperatorRequiresWhitespace]
+// CHECK:STDERR: fail_star_minus.carbon:[[@LINE+4]]:16: error: whitespace missing after binary operator [BinaryOperatorRequiresWhitespace]
 // CHECK:STDERR: var n: i8 = n* -n;
 // CHECK:STDERR:                ^
+// CHECK:STDERR:
 var n: i8 = n* -n;
 
 // CHECK:STDOUT: - filename: fail_star_minus.carbon
diff --git a/toolchain/parse/testdata/operators/fail_star_star.carbon b/toolchain/parse/testdata/operators/fail_star_star.carbon
index 1b63a5b51033..df3cdf61c0a9 100644
--- a/toolchain/parse/testdata/operators/fail_star_star.carbon
+++ b/toolchain/parse/testdata/operators/fail_star_star.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/operators/fail_star_star.carbon
 
-// CHECK:STDERR: fail_star_star.carbon:[[@LINE+3]]:16: error: whitespace missing after binary operator [BinaryOperatorRequiresWhitespace]
+// CHECK:STDERR: fail_star_star.carbon:[[@LINE+4]]:16: error: whitespace missing after binary operator [BinaryOperatorRequiresWhitespace]
 // CHECK:STDERR: var n: i8 = n* *p;
 // CHECK:STDERR:                ^
+// CHECK:STDERR:
 var n: i8 = n* *p;
 
 // CHECK:STDOUT: - filename: fail_star_star.carbon
diff --git a/toolchain/parse/testdata/operators/fail_star_star_no_space.carbon b/toolchain/parse/testdata/operators/fail_star_star_no_space.carbon
index 38e4e3531249..8767552136f2 100644
--- a/toolchain/parse/testdata/operators/fail_star_star_no_space.carbon
+++ b/toolchain/parse/testdata/operators/fail_star_star_no_space.carbon
@@ -12,9 +12,10 @@
 // before we notice the missing whitespace around the second `*`.
 // It'd be better to (somehow) form n*(*p) and reject due to the missing
 // whitespace around the first `*`.
-// CHECK:STDERR: fail_star_star_no_space.carbon:[[@LINE+3]]:16: error: `var` declarations must end with a `;` [ExpectedDeclSemi]
+// CHECK:STDERR: fail_star_star_no_space.carbon:[[@LINE+4]]:16: error: `var` declarations must end with a `;` [ExpectedDeclSemi]
 // CHECK:STDERR: var n: i8 = n**p;
 // CHECK:STDERR:                ^
+// CHECK:STDERR:
 var n: i8 = n**p;
 
 // CHECK:STDOUT: - filename: fail_star_star_no_space.carbon
diff --git a/toolchain/parse/testdata/operators/fail_variety.carbon b/toolchain/parse/testdata/operators/fail_variety.carbon
index 212fcdffc3c1..827d95c61340 100644
--- a/toolchain/parse/testdata/operators/fail_variety.carbon
+++ b/toolchain/parse/testdata/operators/fail_variety.carbon
@@ -9,25 +9,26 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/operators/fail_variety.carbon
 
 fn F() {
-  // CHECK:STDERR: fail_variety.carbon:[[@LINE+19]]:21: error: operator `=` can only be used as a complete statement [StatementOperatorAsSubExpr]
+  // CHECK:STDERR: fail_variety.carbon:[[@LINE+20]]:21: error: operator `=` can only be used as a complete statement [StatementOperatorAsSubExpr]
   // CHECK:STDERR:   n = a * b + c * d = d * d << e & f - not g;
   // CHECK:STDERR:                     ^
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_variety.carbon:[[@LINE+15]]:29: error: parentheses are required to disambiguate operator precedence [OperatorRequiresParentheses]
+  // CHECK:STDERR: fail_variety.carbon:[[@LINE+16]]:29: error: parentheses are required to disambiguate operator precedence [OperatorRequiresParentheses]
   // CHECK:STDERR:   n = a * b + c * d = d * d << e & f - not g;
   // CHECK:STDERR:                             ^~
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_variety.carbon:[[@LINE+11]]:34: error: parentheses are required to disambiguate operator precedence [OperatorRequiresParentheses]
+  // CHECK:STDERR: fail_variety.carbon:[[@LINE+12]]:34: error: parentheses are required to disambiguate operator precedence [OperatorRequiresParentheses]
   // CHECK:STDERR:   n = a * b + c * d = d * d << e & f - not g;
   // CHECK:STDERR:                                  ^
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_variety.carbon:[[@LINE+7]]:38: error: parentheses are required to disambiguate operator precedence [OperatorRequiresParentheses]
+  // CHECK:STDERR: fail_variety.carbon:[[@LINE+8]]:38: error: parentheses are required to disambiguate operator precedence [OperatorRequiresParentheses]
   // CHECK:STDERR:   n = a * b + c * d = d * d << e & f - not g;
   // CHECK:STDERR:                                      ^
   // CHECK:STDERR:
-  // CHECK:STDERR: fail_variety.carbon:[[@LINE+3]]:40: error: parentheses are required around this unary `not` operator [UnaryOperatorRequiresParentheses]
+  // CHECK:STDERR: fail_variety.carbon:[[@LINE+4]]:40: error: parentheses are required around this unary `not` operator [UnaryOperatorRequiresParentheses]
   // CHECK:STDERR:   n = a * b + c * d = d * d << e & f - not g;
   // CHECK:STDERR:                                        ^~~
+  // CHECK:STDERR:
   n = a * b + c * d = d * d << e & f - not g;
 }
 
diff --git a/toolchain/parse/testdata/operators/unary.carbon b/toolchain/parse/testdata/operators/unary.carbon
index 1afc41ecab72..e336a4255520 100644
--- a/toolchain/parse/testdata/operators/unary.carbon
+++ b/toolchain/parse/testdata/operators/unary.carbon
@@ -11,9 +11,10 @@
 // --- fail_space_before.carbon
 
 fn F() {
-  // CHECK:STDERR: fail_space_before.carbon:[[@LINE+3]]:16: error: whitespace is required before this unary operator [UnaryOperatorRequiresWhitespace]
+  // CHECK:STDERR: fail_space_before.carbon:[[@LINE+4]]:16: error: whitespace is required before this unary operator [UnaryOperatorRequiresWhitespace]
   // CHECK:STDERR:   if (false) {}--0;
   // CHECK:STDERR:                ^~
+  // CHECK:STDERR:
   if (false) {}--0;
 }
 
diff --git a/toolchain/parse/testdata/package_expr/fail_in_name.carbon b/toolchain/parse/testdata/package_expr/fail_in_name.carbon
index 4de8e64d9482..d99b4fee38ff 100644
--- a/toolchain/parse/testdata/package_expr/fail_in_name.carbon
+++ b/toolchain/parse/testdata/package_expr/fail_in_name.carbon
@@ -20,9 +20,10 @@ var package.val: i32;
 // CHECK:STDERR:
 namespace package.NS;
 
-// CHECK:STDERR: fail_in_name.carbon:[[@LINE+3]]:7: error: `class` introducer should be followed by a name [ExpectedDeclName]
+// CHECK:STDERR: fail_in_name.carbon:[[@LINE+4]]:7: error: `class` introducer should be followed by a name [ExpectedDeclName]
 // CHECK:STDERR: class package.C {
 // CHECK:STDERR:       ^~~~~~~
+// CHECK:STDERR:
 class package.C {
 }
 
diff --git a/toolchain/parse/testdata/package_expr/fail_standalone.carbon b/toolchain/parse/testdata/package_expr/fail_standalone.carbon
index 7fc2de7ed539..41607d3969e7 100644
--- a/toolchain/parse/testdata/package_expr/fail_standalone.carbon
+++ b/toolchain/parse/testdata/package_expr/fail_standalone.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/package_expr/fail_standalone.carbon
 
 fn F() {
-  // CHECK:STDERR: fail_standalone.carbon:[[@LINE+3]]:10: error: expected `.` after `package` expression [ExpectedPeriodAfterPackage]
+  // CHECK:STDERR: fail_standalone.carbon:[[@LINE+4]]:10: error: expected `.` after `package` expression [ExpectedPeriodAfterPackage]
   // CHECK:STDERR:   package;
   // CHECK:STDERR:          ^
+  // CHECK:STDERR:
   package;
 }
 
diff --git a/toolchain/parse/testdata/packages/export.carbon b/toolchain/parse/testdata/packages/export.carbon
index 5eb16eb8f4fe..4afd5791573b 100644
--- a/toolchain/parse/testdata/packages/export.carbon
+++ b/toolchain/parse/testdata/packages/export.carbon
@@ -129,9 +129,10 @@ export Foo;
 
 impl package Pkg;
 
-// CHECK:STDERR: fail_in_impl.carbon:[[@LINE+3]]:1: error: `export` is only allowed in API files [ExportFromImpl]
+// CHECK:STDERR: fail_in_impl.carbon:[[@LINE+4]]:1: error: `export` is only allowed in API files [ExportFromImpl]
 // CHECK:STDERR: export Foo;
 // CHECK:STDERR: ^~~~~~
+// CHECK:STDERR:
 export Foo;
 
 // CHECK:STDOUT: - filename: lib.carbon
diff --git a/toolchain/parse/testdata/packages/import/export.carbon b/toolchain/parse/testdata/packages/import/export.carbon
index e06a226d7b0e..8f368bd6908e 100644
--- a/toolchain/parse/testdata/packages/import/export.carbon
+++ b/toolchain/parse/testdata/packages/import/export.carbon
@@ -59,9 +59,10 @@ export import library "lib";
 
 impl package Pkg;
 
-// CHECK:STDERR: fail_in_impl.carbon:[[@LINE+3]]:1: error: `export` is only allowed in API files [ExportFromImpl]
+// CHECK:STDERR: fail_in_impl.carbon:[[@LINE+4]]:1: error: `export` is only allowed in API files [ExportFromImpl]
 // CHECK:STDERR: export import library "lib";
 // CHECK:STDERR: ^~~~~~
+// CHECK:STDERR:
 export import library "lib";
 
 // CHECK:STDOUT: - filename: fail_package.carbon
diff --git a/toolchain/parse/testdata/packages/import/fail_after_decl.carbon b/toolchain/parse/testdata/packages/import/fail_after_decl.carbon
index 76ca7e85a8ee..771d47295cc7 100644
--- a/toolchain/parse/testdata/packages/import/fail_after_decl.carbon
+++ b/toolchain/parse/testdata/packages/import/fail_after_decl.carbon
@@ -10,12 +10,13 @@
 
 fn A();
 
-// CHECK:STDERR: fail_after_decl.carbon:[[@LINE+6]]:1: error: `import` declarations must come after the `package` declaration (if present) and before any other entities in the file [ImportTooLate]
+// CHECK:STDERR: fail_after_decl.carbon:[[@LINE+7]]:1: error: `import` declarations must come after the `package` declaration (if present) and before any other entities in the file [ImportTooLate]
 // CHECK:STDERR: import B;
 // CHECK:STDERR: ^~~~~~
 // CHECK:STDERR: fail_after_decl.carbon:[[@LINE-5]]:1: note: first declaration is here [FirstDecl]
 // CHECK:STDERR: fn A();
 // CHECK:STDERR: ^~
+// CHECK:STDERR:
 import B;
 
 // CHECK:STDOUT: - filename: fail_after_decl.carbon
diff --git a/toolchain/parse/testdata/packages/import/fail_after_decl_repeated.carbon b/toolchain/parse/testdata/packages/import/fail_after_decl_repeated.carbon
index f531f0539f2d..98131dc9f2d9 100644
--- a/toolchain/parse/testdata/packages/import/fail_after_decl_repeated.carbon
+++ b/toolchain/parse/testdata/packages/import/fail_after_decl_repeated.carbon
@@ -32,12 +32,13 @@ package D;
 
 fn E();
 
-// CHECK:STDERR: fail_after_decl_repeated.carbon:[[@LINE+6]]:1: error: `import` declarations must come after the `package` declaration (if present) and before any other entities in the file [ImportTooLate]
+// CHECK:STDERR: fail_after_decl_repeated.carbon:[[@LINE+7]]:1: error: `import` declarations must come after the `package` declaration (if present) and before any other entities in the file [ImportTooLate]
 // CHECK:STDERR: import F;
 // CHECK:STDERR: ^~~~~~
 // CHECK:STDERR: fail_after_decl_repeated.carbon:[[@LINE-27]]:1: note: first declaration is here [FirstDecl]
 // CHECK:STDERR: fn A();
 // CHECK:STDERR: ^~
+// CHECK:STDERR:
 import F;
 // Note this is still invalid, but doesn't warn because it's sequential.
 import G;
diff --git a/toolchain/parse/testdata/packages/import/fail_extra_string.carbon b/toolchain/parse/testdata/packages/import/fail_extra_string.carbon
index 6880a5af7511..a7d0a0edb928 100644
--- a/toolchain/parse/testdata/packages/import/fail_extra_string.carbon
+++ b/toolchain/parse/testdata/packages/import/fail_extra_string.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/packages/import/fail_extra_string.carbon
 
-// CHECK:STDERR: fail_extra_string.carbon:[[@LINE+3]]:26: error: `import` declarations must end with a `;` [ExpectedDeclSemi]
+// CHECK:STDERR: fail_extra_string.carbon:[[@LINE+4]]:26: error: `import` declarations must end with a `;` [ExpectedDeclSemi]
 // CHECK:STDERR: import Foo library "bar" "baz";
 // CHECK:STDERR:                          ^~~~~
+// CHECK:STDERR:
 import Foo library "bar" "baz";
 
 // CHECK:STDOUT: - filename: fail_extra_string.carbon
diff --git a/toolchain/parse/testdata/packages/import/fail_in_nested_scope.carbon b/toolchain/parse/testdata/packages/import/fail_in_nested_scope.carbon
index a7900c1bc861..c47f72ef69f0 100644
--- a/toolchain/parse/testdata/packages/import/fail_in_nested_scope.carbon
+++ b/toolchain/parse/testdata/packages/import/fail_in_nested_scope.carbon
@@ -20,12 +20,13 @@ class A {
 }
 
 fn F() {
-  // CHECK:STDERR: fail_in_nested_scope.carbon:[[@LINE+6]]:3: error: `import` declarations must come after the `package` declaration (if present) and before any other entities in the file [ImportTooLate]
+  // CHECK:STDERR: fail_in_nested_scope.carbon:[[@LINE+7]]:3: error: `import` declarations must come after the `package` declaration (if present) and before any other entities in the file [ImportTooLate]
   // CHECK:STDERR:   import C;
   // CHECK:STDERR:   ^~~~~~
   // CHECK:STDERR: fail_in_nested_scope.carbon:[[@LINE-15]]:1: note: first declaration is here [FirstDecl]
   // CHECK:STDERR: class A {
   // CHECK:STDERR: ^~~~~
+  // CHECK:STDERR:
   import C;
 }
 
diff --git a/toolchain/parse/testdata/packages/import/fail_library_is_identifier.carbon b/toolchain/parse/testdata/packages/import/fail_library_is_identifier.carbon
index 5a592ae90c21..78013661d2d0 100644
--- a/toolchain/parse/testdata/packages/import/fail_library_is_identifier.carbon
+++ b/toolchain/parse/testdata/packages/import/fail_library_is_identifier.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/packages/import/fail_library_is_identifier.carbon
 
-// CHECK:STDERR: fail_library_is_identifier.carbon:[[@LINE+3]]:25: error: expected a string literal to specify the library name [ExpectedLibraryName]
+// CHECK:STDERR: fail_library_is_identifier.carbon:[[@LINE+4]]:25: error: expected a string literal to specify the library name [ExpectedLibraryName]
 // CHECK:STDERR: import Geometry library Shapes;
 // CHECK:STDERR:                         ^~~~~~
+// CHECK:STDERR:
 import Geometry library Shapes;
 
 // CHECK:STDOUT: - filename: fail_library_is_identifier.carbon
diff --git a/toolchain/parse/testdata/packages/import/fail_name_is_keyword.carbon b/toolchain/parse/testdata/packages/import/fail_name_is_keyword.carbon
index 829bb50baeb7..64191bc6ecb8 100644
--- a/toolchain/parse/testdata/packages/import/fail_name_is_keyword.carbon
+++ b/toolchain/parse/testdata/packages/import/fail_name_is_keyword.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/packages/import/fail_name_is_keyword.carbon
 
-// CHECK:STDERR: fail_name_is_keyword.carbon:[[@LINE+3]]:8: error: expected identifier or `library` after `import` [ExpectedIdentifierAfterImport]
+// CHECK:STDERR: fail_name_is_keyword.carbon:[[@LINE+4]]:8: error: expected identifier or `library` after `import` [ExpectedIdentifierAfterImport]
 // CHECK:STDERR: import fn;
 // CHECK:STDERR:        ^~
+// CHECK:STDERR:
 import fn;
 
 // CHECK:STDOUT: - filename: fail_name_is_keyword.carbon
diff --git a/toolchain/parse/testdata/packages/import/fail_no_name.carbon b/toolchain/parse/testdata/packages/import/fail_no_name.carbon
index 6b92d2599e45..9a15b78449d1 100644
--- a/toolchain/parse/testdata/packages/import/fail_no_name.carbon
+++ b/toolchain/parse/testdata/packages/import/fail_no_name.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/packages/import/fail_no_name.carbon
 
-// CHECK:STDERR: fail_no_name.carbon:[[@LINE+3]]:7: error: expected identifier or `library` after `import` [ExpectedIdentifierAfterImport]
+// CHECK:STDERR: fail_no_name.carbon:[[@LINE+4]]:7: error: expected identifier or `library` after `import` [ExpectedIdentifierAfterImport]
 // CHECK:STDERR: import;
 // CHECK:STDERR:       ^
+// CHECK:STDERR:
 import;
 
 // CHECK:STDOUT: - filename: fail_no_name.carbon
diff --git a/toolchain/parse/testdata/packages/import/fail_no_semi.carbon b/toolchain/parse/testdata/packages/import/fail_no_semi.carbon
index 0b116941ae66..591b6e38f13f 100644
--- a/toolchain/parse/testdata/packages/import/fail_no_semi.carbon
+++ b/toolchain/parse/testdata/packages/import/fail_no_semi.carbon
@@ -10,9 +10,10 @@
 
 import Geometry
 
-// CHECK:STDERR: fail_no_semi.carbon:[[@LINE+10]]:21: error: `import` declarations must end with a `;` [ExpectedDeclSemi]
+// CHECK:STDERR: fail_no_semi.carbon:[[@LINE+11]]:21: error: `import` declarations must end with a `;` [ExpectedDeclSemi]
 // CHECK:STDERR: // CHECK:STDOUT:   ]
 // CHECK:STDERR:                     ^
+// CHECK:STDERR:
 // CHECK:STDOUT: - filename: fail_no_semi.carbon
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
diff --git a/toolchain/parse/testdata/packages/import/fail_omit_library_keyword.carbon b/toolchain/parse/testdata/packages/import/fail_omit_library_keyword.carbon
index 7d0a094e155b..e3ce4963d20b 100644
--- a/toolchain/parse/testdata/packages/import/fail_omit_library_keyword.carbon
+++ b/toolchain/parse/testdata/packages/import/fail_omit_library_keyword.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/packages/import/fail_omit_library_keyword.carbon
 
-// CHECK:STDERR: fail_omit_library_keyword.carbon:[[@LINE+3]]:17: error: missing `library` keyword [MissingLibraryKeyword]
+// CHECK:STDERR: fail_omit_library_keyword.carbon:[[@LINE+4]]:17: error: missing `library` keyword [MissingLibraryKeyword]
 // CHECK:STDERR: import Geometry "Shapes";
 // CHECK:STDERR:                 ^~~~~~~~
+// CHECK:STDERR:
 import Geometry "Shapes";
 
 // CHECK:STDOUT: - filename: fail_omit_library_keyword.carbon
diff --git a/toolchain/parse/testdata/packages/import/fail_type.carbon b/toolchain/parse/testdata/packages/import/fail_type.carbon
index 4a98a7e2fd49..9f0bec87d514 100644
--- a/toolchain/parse/testdata/packages/import/fail_type.carbon
+++ b/toolchain/parse/testdata/packages/import/fail_type.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/packages/import/fail_type.carbon
 
-// CHECK:STDERR: fail_type.carbon:[[@LINE+3]]:17: error: `import` declarations must end with a `;` [ExpectedDeclSemi]
+// CHECK:STDERR: fail_type.carbon:[[@LINE+4]]:17: error: `import` declarations must end with a `;` [ExpectedDeclSemi]
 // CHECK:STDERR: import Geometry api;
 // CHECK:STDERR:                 ^~~
+// CHECK:STDERR:
 import Geometry api;
 
 // CHECK:STDOUT: - filename: fail_type.carbon
diff --git a/toolchain/parse/testdata/packages/library/fail_in_nested_scope.carbon b/toolchain/parse/testdata/packages/library/fail_in_nested_scope.carbon
index 927130f4953a..35756b0e03a2 100644
--- a/toolchain/parse/testdata/packages/library/fail_in_nested_scope.carbon
+++ b/toolchain/parse/testdata/packages/library/fail_in_nested_scope.carbon
@@ -46,12 +46,13 @@ class C {
 }
 
 fn F() {
-  // CHECK:STDERR: fail_in_nested_scope.carbon:[[@LINE+6]]:3: error: the `library` declaration must be the first non-comment line [PackageTooLate]
+  // CHECK:STDERR: fail_in_nested_scope.carbon:[[@LINE+7]]:3: error: the `library` declaration must be the first non-comment line [PackageTooLate]
   // CHECK:STDERR:   impl library "foo";
   // CHECK:STDERR:   ^~~~
   // CHECK:STDERR: fail_in_nested_scope.carbon:[[@LINE-39]]:1: note: first non-comment line is here [FirstNonCommentLine]
   // CHECK:STDERR: class C {
   // CHECK:STDERR: ^~~~~
+  // CHECK:STDERR:
   impl library "foo";
 }
 
diff --git a/toolchain/parse/testdata/packages/library/fail_invalid_name.carbon b/toolchain/parse/testdata/packages/library/fail_invalid_name.carbon
index 9bdf3e42977c..744efed8c585 100644
--- a/toolchain/parse/testdata/packages/library/fail_invalid_name.carbon
+++ b/toolchain/parse/testdata/packages/library/fail_invalid_name.carbon
@@ -52,9 +52,10 @@ library "[[@TEST_NAME]]" impl
 
 library "[[@TEST_NAME]]"
 
-// CHECK:STDERR: fail_no_semi.carbon:[[@LINE+46]]:21: error: `library` declarations must end with a `;` [ExpectedDeclSemi]
+// CHECK:STDERR: fail_no_semi.carbon:[[@LINE+47]]:21: error: `library` declarations must end with a `;` [ExpectedDeclSemi]
 // CHECK:STDERR: // CHECK:STDOUT:   ]
 // CHECK:STDERR:                     ^
+// CHECK:STDERR:
 // CHECK:STDOUT: - filename: fail_identifier.carbon
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
diff --git a/toolchain/parse/testdata/packages/library/fail_semi_before.carbon b/toolchain/parse/testdata/packages/library/fail_semi_before.carbon
index c7249d6e4c5b..00ec73b65c84 100644
--- a/toolchain/parse/testdata/packages/library/fail_semi_before.carbon
+++ b/toolchain/parse/testdata/packages/library/fail_semi_before.carbon
@@ -10,12 +10,13 @@
 
 ;
 
-// CHECK:STDERR: fail_semi_before.carbon:[[@LINE+6]]:1: error: the `library` declaration must be the first non-comment line [PackageTooLate]
+// CHECK:STDERR: fail_semi_before.carbon:[[@LINE+7]]:1: error: the `library` declaration must be the first non-comment line [PackageTooLate]
 // CHECK:STDERR: library "semi_before";
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR: fail_semi_before.carbon:[[@LINE-5]]:1: note: first non-comment line is here [FirstNonCommentLine]
 // CHECK:STDERR: ;
 // CHECK:STDERR: ^
+// CHECK:STDERR:
 library "[[@TEST_NAME]]";
 
 // CHECK:STDOUT: - filename: fail_semi_before.carbon
diff --git a/toolchain/parse/testdata/packages/library/fail_too_late.carbon b/toolchain/parse/testdata/packages/library/fail_too_late.carbon
index 59c9285ea87e..1aac94ca691f 100644
--- a/toolchain/parse/testdata/packages/library/fail_too_late.carbon
+++ b/toolchain/parse/testdata/packages/library/fail_too_late.carbon
@@ -10,12 +10,13 @@
 
 import Geometry;
 
-// CHECK:STDERR: fail_too_late.carbon:[[@LINE+6]]:1: error: the `library` declaration must be the first non-comment line [PackageTooLate]
+// CHECK:STDERR: fail_too_late.carbon:[[@LINE+7]]:1: error: the `library` declaration must be the first non-comment line [PackageTooLate]
 // CHECK:STDERR: library "too_late";
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR: fail_too_late.carbon:[[@LINE-5]]:1: note: first non-comment line is here [FirstNonCommentLine]
 // CHECK:STDERR: import Geometry;
 // CHECK:STDERR: ^~~~~~
+// CHECK:STDERR:
 library "[[@TEST_NAME]]";
 
 // CHECK:STDOUT: - filename: fail_too_late.carbon
diff --git a/toolchain/parse/testdata/packages/package/fail_after_decl.carbon b/toolchain/parse/testdata/packages/package/fail_after_decl.carbon
index a87c4eeff66a..9135cab09100 100644
--- a/toolchain/parse/testdata/packages/package/fail_after_decl.carbon
+++ b/toolchain/parse/testdata/packages/package/fail_after_decl.carbon
@@ -10,12 +10,13 @@
 
 fn A();
 
-// CHECK:STDERR: fail_after_decl.carbon:[[@LINE+6]]:1: error: the `package` declaration must be the first non-comment line [PackageTooLate]
+// CHECK:STDERR: fail_after_decl.carbon:[[@LINE+7]]:1: error: the `package` declaration must be the first non-comment line [PackageTooLate]
 // CHECK:STDERR: package B;
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR: fail_after_decl.carbon:[[@LINE-5]]:1: note: first non-comment line is here [FirstNonCommentLine]
 // CHECK:STDERR: fn A();
 // CHECK:STDERR: ^~
+// CHECK:STDERR:
 package B;
 
 // CHECK:STDOUT: - filename: fail_after_decl.carbon
diff --git a/toolchain/parse/testdata/packages/package/fail_after_import.carbon b/toolchain/parse/testdata/packages/package/fail_after_import.carbon
index 3604c60a0192..038f992956ef 100644
--- a/toolchain/parse/testdata/packages/package/fail_after_import.carbon
+++ b/toolchain/parse/testdata/packages/package/fail_after_import.carbon
@@ -10,12 +10,13 @@
 
 import A;
 
-// CHECK:STDERR: fail_after_import.carbon:[[@LINE+6]]:1: error: the `package` declaration must be the first non-comment line [PackageTooLate]
+// CHECK:STDERR: fail_after_import.carbon:[[@LINE+7]]:1: error: the `package` declaration must be the first non-comment line [PackageTooLate]
 // CHECK:STDERR: package B;
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR: fail_after_import.carbon:[[@LINE-5]]:1: note: first non-comment line is here [FirstNonCommentLine]
 // CHECK:STDERR: import A;
 // CHECK:STDERR: ^~~~~~
+// CHECK:STDERR:
 package B;
 
 // CHECK:STDOUT: - filename: fail_after_import.carbon
diff --git a/toolchain/parse/testdata/packages/package/fail_after_package.carbon b/toolchain/parse/testdata/packages/package/fail_after_package.carbon
index f895b1112a99..ecc4cdf3cde2 100644
--- a/toolchain/parse/testdata/packages/package/fail_after_package.carbon
+++ b/toolchain/parse/testdata/packages/package/fail_after_package.carbon
@@ -9,12 +9,13 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/packages/package/fail_after_package.carbon
 
 package A;
-// CHECK:STDERR: fail_after_package.carbon:[[@LINE+6]]:1: error: the `package` declaration must be the first non-comment line [PackageTooLate]
+// CHECK:STDERR: fail_after_package.carbon:[[@LINE+7]]:1: error: the `package` declaration must be the first non-comment line [PackageTooLate]
 // CHECK:STDERR: package B;
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR: fail_after_package.carbon:[[@LINE-4]]:1: note: first non-comment line is here [FirstNonCommentLine]
 // CHECK:STDERR: package A;
 // CHECK:STDERR: ^~~~~~~
+// CHECK:STDERR:
 package B;
 
 // CHECK:STDOUT: - filename: fail_after_package.carbon
diff --git a/toolchain/parse/testdata/packages/package/fail_extra_string.carbon b/toolchain/parse/testdata/packages/package/fail_extra_string.carbon
index 785541861d4e..b7db4cb3c3f5 100644
--- a/toolchain/parse/testdata/packages/package/fail_extra_string.carbon
+++ b/toolchain/parse/testdata/packages/package/fail_extra_string.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/packages/package/fail_extra_string.carbon
 
-// CHECK:STDERR: fail_extra_string.carbon:[[@LINE+3]]:27: error: `package` declarations must end with a `;` [ExpectedDeclSemi]
+// CHECK:STDERR: fail_extra_string.carbon:[[@LINE+4]]:27: error: `package` declarations must end with a `;` [ExpectedDeclSemi]
 // CHECK:STDERR: package Foo library "bar" "baz";
 // CHECK:STDERR:                           ^~~~~
+// CHECK:STDERR:
 package Foo library "bar" "baz";
 
 // CHECK:STDOUT: - filename: fail_extra_string.carbon
diff --git a/toolchain/parse/testdata/packages/package/fail_in_nested_scope.carbon b/toolchain/parse/testdata/packages/package/fail_in_nested_scope.carbon
index 0652a435e58d..d2ac1830782e 100644
--- a/toolchain/parse/testdata/packages/package/fail_in_nested_scope.carbon
+++ b/toolchain/parse/testdata/packages/package/fail_in_nested_scope.carbon
@@ -48,12 +48,13 @@ class C {
 
 fn F() {
   // This reaches decl parsing because `impl` is a valid modifier or introducer.
-  // CHECK:STDERR: fail_in_nested_scope.carbon:[[@LINE+6]]:3: error: the `package` declaration must be the first non-comment line [PackageTooLate]
+  // CHECK:STDERR: fail_in_nested_scope.carbon:[[@LINE+7]]:3: error: the `package` declaration must be the first non-comment line [PackageTooLate]
   // CHECK:STDERR:   impl package P;
   // CHECK:STDERR:   ^~~~
   // CHECK:STDERR: fail_in_nested_scope.carbon:[[@LINE-41]]:1: note: first non-comment line is here [FirstNonCommentLine]
   // CHECK:STDERR: class C {
   // CHECK:STDERR: ^~~~~
+  // CHECK:STDERR:
   impl package P;
 }
 
diff --git a/toolchain/parse/testdata/packages/package/fail_library_is_identifier.carbon b/toolchain/parse/testdata/packages/package/fail_library_is_identifier.carbon
index 925199d661f2..fc9ca38b1b2b 100644
--- a/toolchain/parse/testdata/packages/package/fail_library_is_identifier.carbon
+++ b/toolchain/parse/testdata/packages/package/fail_library_is_identifier.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/packages/package/fail_library_is_identifier.carbon
 
-// CHECK:STDERR: fail_library_is_identifier.carbon:[[@LINE+3]]:26: error: expected a string literal to specify the library name [ExpectedLibraryName]
+// CHECK:STDERR: fail_library_is_identifier.carbon:[[@LINE+4]]:26: error: expected a string literal to specify the library name [ExpectedLibraryName]
 // CHECK:STDERR: package Geometry library Shapes;
 // CHECK:STDERR:                          ^~~~~~
+// CHECK:STDERR:
 package Geometry library Shapes;
 
 // CHECK:STDOUT: - filename: fail_library_is_identifier.carbon
diff --git a/toolchain/parse/testdata/packages/package/fail_library_skips_name.carbon b/toolchain/parse/testdata/packages/package/fail_library_skips_name.carbon
index c63e8e329604..bf7a831b90c3 100644
--- a/toolchain/parse/testdata/packages/package/fail_library_skips_name.carbon
+++ b/toolchain/parse/testdata/packages/package/fail_library_skips_name.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/packages/package/fail_library_skips_name.carbon
 
-// CHECK:STDERR: fail_library_skips_name.carbon:[[@LINE+3]]:9: error: expected identifier after `package` [ExpectedIdentifierAfterPackage]
+// CHECK:STDERR: fail_library_skips_name.carbon:[[@LINE+4]]:9: error: expected identifier after `package` [ExpectedIdentifierAfterPackage]
 // CHECK:STDERR: package library "Shapes";
 // CHECK:STDERR:         ^~~~~~~
+// CHECK:STDERR:
 package library "Shapes";
 
 // CHECK:STDOUT: - filename: fail_library_skips_name.carbon
diff --git a/toolchain/parse/testdata/packages/package/fail_name_is_keyword.carbon b/toolchain/parse/testdata/packages/package/fail_name_is_keyword.carbon
index 0caf38cdf232..e33629150eac 100644
--- a/toolchain/parse/testdata/packages/package/fail_name_is_keyword.carbon
+++ b/toolchain/parse/testdata/packages/package/fail_name_is_keyword.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/packages/package/fail_name_is_keyword.carbon
 
-// CHECK:STDERR: fail_name_is_keyword.carbon:[[@LINE+3]]:9: error: expected identifier after `package` [ExpectedIdentifierAfterPackage]
+// CHECK:STDERR: fail_name_is_keyword.carbon:[[@LINE+4]]:9: error: expected identifier after `package` [ExpectedIdentifierAfterPackage]
 // CHECK:STDERR: package fn;
 // CHECK:STDERR:         ^~
+// CHECK:STDERR:
 package fn;
 
 // CHECK:STDOUT: - filename: fail_name_is_keyword.carbon
diff --git a/toolchain/parse/testdata/packages/package/fail_no_name.carbon b/toolchain/parse/testdata/packages/package/fail_no_name.carbon
index 3a64a8710e58..0929534bff04 100644
--- a/toolchain/parse/testdata/packages/package/fail_no_name.carbon
+++ b/toolchain/parse/testdata/packages/package/fail_no_name.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/packages/package/fail_no_name.carbon
 
-// CHECK:STDERR: fail_no_name.carbon:[[@LINE+3]]:8: error: expected identifier after `package` [ExpectedIdentifierAfterPackage]
+// CHECK:STDERR: fail_no_name.carbon:[[@LINE+4]]:8: error: expected identifier after `package` [ExpectedIdentifierAfterPackage]
 // CHECK:STDERR: package;
 // CHECK:STDERR:        ^
+// CHECK:STDERR:
 package;
 
 // CHECK:STDOUT: - filename: fail_no_name.carbon
diff --git a/toolchain/parse/testdata/packages/package/fail_no_semi.carbon b/toolchain/parse/testdata/packages/package/fail_no_semi.carbon
index 2e742be21238..3ea7c1e1408a 100644
--- a/toolchain/parse/testdata/packages/package/fail_no_semi.carbon
+++ b/toolchain/parse/testdata/packages/package/fail_no_semi.carbon
@@ -10,9 +10,10 @@
 
 package Geometry
 
-// CHECK:STDERR: fail_no_semi.carbon:[[@LINE+10]]:21: error: `package` declarations must end with a `;` [ExpectedDeclSemi]
+// CHECK:STDERR: fail_no_semi.carbon:[[@LINE+11]]:21: error: `package` declarations must end with a `;` [ExpectedDeclSemi]
 // CHECK:STDERR: // CHECK:STDOUT:   ]
 // CHECK:STDERR:                     ^
+// CHECK:STDERR:
 // CHECK:STDOUT: - filename: fail_no_semi.carbon
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
diff --git a/toolchain/parse/testdata/packages/package/fail_omit_library_keyword.carbon b/toolchain/parse/testdata/packages/package/fail_omit_library_keyword.carbon
index 6d47d984c3ad..6d6ae2b48bb2 100644
--- a/toolchain/parse/testdata/packages/package/fail_omit_library_keyword.carbon
+++ b/toolchain/parse/testdata/packages/package/fail_omit_library_keyword.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/packages/package/fail_omit_library_keyword.carbon
 
-// CHECK:STDERR: fail_omit_library_keyword.carbon:[[@LINE+3]]:18: error: missing `library` keyword [MissingLibraryKeyword]
+// CHECK:STDERR: fail_omit_library_keyword.carbon:[[@LINE+4]]:18: error: missing `library` keyword [MissingLibraryKeyword]
 // CHECK:STDERR: package Geometry "Shapes";
 // CHECK:STDERR:                  ^~~~~~~~
+// CHECK:STDERR:
 package Geometry "Shapes";
 
 // CHECK:STDOUT: - filename: fail_omit_library_keyword.carbon
diff --git a/toolchain/parse/testdata/packages/package/fail_semi_before.carbon b/toolchain/parse/testdata/packages/package/fail_semi_before.carbon
index 3096ee9d63f1..8952c3e8d029 100644
--- a/toolchain/parse/testdata/packages/package/fail_semi_before.carbon
+++ b/toolchain/parse/testdata/packages/package/fail_semi_before.carbon
@@ -10,12 +10,13 @@
 
 ;
 
-// CHECK:STDERR: fail_semi_before.carbon:[[@LINE+6]]:1: error: the `package` declaration must be the first non-comment line [PackageTooLate]
+// CHECK:STDERR: fail_semi_before.carbon:[[@LINE+7]]:1: error: the `package` declaration must be the first non-comment line [PackageTooLate]
 // CHECK:STDERR: package Geometry;
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR: fail_semi_before.carbon:[[@LINE-5]]:1: note: first non-comment line is here [FirstNonCommentLine]
 // CHECK:STDERR: ;
 // CHECK:STDERR: ^
+// CHECK:STDERR:
 package Geometry;
 
 // CHECK:STDOUT: - filename: fail_semi_before.carbon
diff --git a/toolchain/parse/testdata/packages/package/fail_trailing_impl.carbon b/toolchain/parse/testdata/packages/package/fail_trailing_impl.carbon
index 3563980f35e0..1c13eb19fa8c 100644
--- a/toolchain/parse/testdata/packages/package/fail_trailing_impl.carbon
+++ b/toolchain/parse/testdata/packages/package/fail_trailing_impl.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/packages/package/fail_trailing_impl.carbon
 
-// CHECK:STDERR: fail_trailing_impl.carbon:[[@LINE+3]]:18: error: `package` declarations must end with a `;` [ExpectedDeclSemi]
+// CHECK:STDERR: fail_trailing_impl.carbon:[[@LINE+4]]:18: error: `package` declarations must end with a `;` [ExpectedDeclSemi]
 // CHECK:STDERR: package Geometry impl;
 // CHECK:STDERR:                  ^~~~
+// CHECK:STDERR:
 package Geometry impl;
 
 // CHECK:STDOUT: - filename: fail_trailing_impl.carbon
diff --git a/toolchain/parse/testdata/pointer/fail_pointer_type_in_expr.carbon b/toolchain/parse/testdata/pointer/fail_pointer_type_in_expr.carbon
index ad3b49d9ca3a..1a0da65dcf7c 100644
--- a/toolchain/parse/testdata/pointer/fail_pointer_type_in_expr.carbon
+++ b/toolchain/parse/testdata/pointer/fail_pointer_type_in_expr.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/pointer/fail_pointer_type_in_expr.carbon
 
 fn F() -> i32 {
-  // CHECK:STDERR: fail_pointer_type_in_expr.carbon:[[@LINE+3]]:14: error: parentheses are required to disambiguate operator precedence [OperatorRequiresParentheses]
+  // CHECK:STDERR: fail_pointer_type_in_expr.carbon:[[@LINE+4]]:14: error: parentheses are required to disambiguate operator precedence [OperatorRequiresParentheses]
   // CHECK:STDERR:   return *i32*;
   // CHECK:STDERR:              ^
+  // CHECK:STDERR:
   return *i32*;
 }
 
diff --git a/toolchain/parse/testdata/pointer/fail_tuple_instead_of_compound_member_access.carbon b/toolchain/parse/testdata/pointer/fail_tuple_instead_of_compound_member_access.carbon
index 02de2fea2835..7c1a9f57c0a4 100644
--- a/toolchain/parse/testdata/pointer/fail_tuple_instead_of_compound_member_access.carbon
+++ b/toolchain/parse/testdata/pointer/fail_tuple_instead_of_compound_member_access.carbon
@@ -51,9 +51,10 @@ fn F() {
   // CHECK:STDERR:
   t->(2, 3);
 
-  // CHECK:STDERR: fail_tuple_instead_of_compound_member_access.carbon:[[@LINE+3]]:9: error: expected `)` [UnexpectedTokenInCompoundMemberAccess]
+  // CHECK:STDERR: fail_tuple_instead_of_compound_member_access.carbon:[[@LINE+4]]:9: error: expected `)` [UnexpectedTokenInCompoundMemberAccess]
   // CHECK:STDERR:   s->(g h i ());
   // CHECK:STDERR:         ^
+  // CHECK:STDERR:
   s->(g h i ());
 }
 
diff --git a/toolchain/parse/testdata/return/fail_expr_no_semi.carbon b/toolchain/parse/testdata/return/fail_expr_no_semi.carbon
index ebd9d229dbe2..5ef845d07bc4 100644
--- a/toolchain/parse/testdata/return/fail_expr_no_semi.carbon
+++ b/toolchain/parse/testdata/return/fail_expr_no_semi.carbon
@@ -10,9 +10,10 @@
 
 fn F() {
   return x
-// CHECK:STDERR: fail_expr_no_semi.carbon:[[@LINE+3]]:1: error: `return` statements must end with a `;` [ExpectedStatementSemi]
+// CHECK:STDERR: fail_expr_no_semi.carbon:[[@LINE+4]]:1: error: `return` statements must end with a `;` [ExpectedStatementSemi]
 // CHECK:STDERR: }
 // CHECK:STDERR: ^
+// CHECK:STDERR:
 }
 
 // CHECK:STDOUT: - filename: fail_expr_no_semi.carbon
diff --git a/toolchain/parse/testdata/return/fail_no_semi.carbon b/toolchain/parse/testdata/return/fail_no_semi.carbon
index 2b1c3f03143f..4ffa13762468 100644
--- a/toolchain/parse/testdata/return/fail_no_semi.carbon
+++ b/toolchain/parse/testdata/return/fail_no_semi.carbon
@@ -10,13 +10,14 @@
 
 fn F() {
   return
-// CHECK:STDERR: fail_no_semi.carbon:[[@LINE+7]]:1: error: expected expression [ExpectedExpr]
+// CHECK:STDERR: fail_no_semi.carbon:[[@LINE+8]]:1: error: expected expression [ExpectedExpr]
 // CHECK:STDERR: }
 // CHECK:STDERR: ^
 // CHECK:STDERR:
-// CHECK:STDERR: fail_no_semi.carbon:[[@LINE+3]]:1: error: `return` statements must end with a `;` [ExpectedStatementSemi]
+// CHECK:STDERR: fail_no_semi.carbon:[[@LINE+4]]:1: error: `return` statements must end with a `;` [ExpectedStatementSemi]
 // CHECK:STDERR: }
 // CHECK:STDERR: ^
+// CHECK:STDERR:
 }
 
 // CHECK:STDOUT: - filename: fail_no_semi.carbon
diff --git a/toolchain/parse/testdata/return/fail_returned_no_var.carbon b/toolchain/parse/testdata/return/fail_returned_no_var.carbon
index fbbf4dee5361..c6bb1d35b5eb 100644
--- a/toolchain/parse/testdata/return/fail_returned_no_var.carbon
+++ b/toolchain/parse/testdata/return/fail_returned_no_var.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/return/fail_returned_no_var.carbon
 
 fn F() -> String {
-  // CHECK:STDERR: fail_returned_no_var.carbon:[[@LINE+3]]:12: error: expected `var` after `returned` [ExpectedVarAfterReturned]
+  // CHECK:STDERR: fail_returned_no_var.carbon:[[@LINE+4]]:12: error: expected `var` after `returned` [ExpectedVarAfterReturned]
   // CHECK:STDERR:   returned fn G() -> i32;
   // CHECK:STDERR:            ^~
+  // CHECK:STDERR:
   returned fn G() -> i32;
 }
 
diff --git a/toolchain/parse/testdata/return/fail_var_no_semi.carbon b/toolchain/parse/testdata/return/fail_var_no_semi.carbon
index e6cc5d4c5bb6..e944a647acab 100644
--- a/toolchain/parse/testdata/return/fail_var_no_semi.carbon
+++ b/toolchain/parse/testdata/return/fail_var_no_semi.carbon
@@ -10,9 +10,10 @@
 
 fn F() {
   return var
-// CHECK:STDERR: fail_var_no_semi.carbon:[[@LINE+3]]:1: error: `return` statements must end with a `;` [ExpectedStatementSemi]
+// CHECK:STDERR: fail_var_no_semi.carbon:[[@LINE+4]]:1: error: `return` statements must end with a `;` [ExpectedStatementSemi]
 // CHECK:STDERR: }
 // CHECK:STDERR: ^
+// CHECK:STDERR:
 }
 
 // CHECK:STDOUT: - filename: fail_var_no_semi.carbon
diff --git a/toolchain/parse/testdata/struct/fail_comma_only.carbon b/toolchain/parse/testdata/struct/fail_comma_only.carbon
index 85dd0e3994eb..c38f094d214c 100644
--- a/toolchain/parse/testdata/struct/fail_comma_only.carbon
+++ b/toolchain/parse/testdata/struct/fail_comma_only.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/struct/fail_comma_only.carbon
 
-// CHECK:STDERR: fail_comma_only.carbon:[[@LINE+3]]:9: error: expected `.field: field_type` or `.field = value` [ExpectedStructLiteralField]
+// CHECK:STDERR: fail_comma_only.carbon:[[@LINE+4]]:9: error: expected `.field: field_type` or `.field = value` [ExpectedStructLiteralField]
 // CHECK:STDERR: var x: {,} = {};
 // CHECK:STDERR:         ^
+// CHECK:STDERR:
 var x: {,} = {};
 
 // CHECK:STDOUT: - filename: fail_comma_only.carbon
diff --git a/toolchain/parse/testdata/struct/fail_comma_repeat_in_type.carbon b/toolchain/parse/testdata/struct/fail_comma_repeat_in_type.carbon
index 2ee4ff188883..39584d048a1e 100644
--- a/toolchain/parse/testdata/struct/fail_comma_repeat_in_type.carbon
+++ b/toolchain/parse/testdata/struct/fail_comma_repeat_in_type.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/struct/fail_comma_repeat_in_type.carbon
 
-// CHECK:STDERR: fail_comma_repeat_in_type.carbon:[[@LINE+3]]:17: error: expected `.field: field_type` [ExpectedStructLiteralField]
+// CHECK:STDERR: fail_comma_repeat_in_type.carbon:[[@LINE+4]]:17: error: expected `.field: field_type` [ExpectedStructLiteralField]
 // CHECK:STDERR: var x: {.a: i32,,} = {};
 // CHECK:STDERR:                 ^
+// CHECK:STDERR:
 var x: {.a: i32,,} = {};
 
 // CHECK:STDOUT: - filename: fail_comma_repeat_in_type.carbon
diff --git a/toolchain/parse/testdata/struct/fail_comma_repeat_in_value.carbon b/toolchain/parse/testdata/struct/fail_comma_repeat_in_value.carbon
index 1430ef5aea1f..17bc7a8572d5 100644
--- a/toolchain/parse/testdata/struct/fail_comma_repeat_in_value.carbon
+++ b/toolchain/parse/testdata/struct/fail_comma_repeat_in_value.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/struct/fail_comma_repeat_in_value.carbon
 
-// CHECK:STDERR: fail_comma_repeat_in_value.carbon:[[@LINE+3]]:16: error: expected `.field = value` [ExpectedStructLiteralField]
+// CHECK:STDERR: fail_comma_repeat_in_value.carbon:[[@LINE+4]]:16: error: expected `.field = value` [ExpectedStructLiteralField]
 // CHECK:STDERR: var x: {.a = 0,,} = {};
 // CHECK:STDERR:                ^
+// CHECK:STDERR:
 var x: {.a = 0,,} = {};
 
 // CHECK:STDOUT: - filename: fail_comma_repeat_in_value.carbon
diff --git a/toolchain/parse/testdata/struct/fail_extra_token_in_type.carbon b/toolchain/parse/testdata/struct/fail_extra_token_in_type.carbon
index 4411a25796f5..218ae72e632e 100644
--- a/toolchain/parse/testdata/struct/fail_extra_token_in_type.carbon
+++ b/toolchain/parse/testdata/struct/fail_extra_token_in_type.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/struct/fail_extra_token_in_type.carbon
 
-// CHECK:STDERR: fail_extra_token_in_type.carbon:[[@LINE+3]]:17: error: expected `,` or `}` [UnexpectedTokenAfterListElement]
+// CHECK:STDERR: fail_extra_token_in_type.carbon:[[@LINE+4]]:17: error: expected `,` or `}` [UnexpectedTokenAfterListElement]
 // CHECK:STDERR: var x: {.a: i32 banana} = {.a = 0};
 // CHECK:STDERR:                 ^~~~~~
+// CHECK:STDERR:
 var x: {.a: i32 banana} = {.a = 0};
 
 // CHECK:STDOUT: - filename: fail_extra_token_in_type.carbon
diff --git a/toolchain/parse/testdata/struct/fail_extra_token_in_value.carbon b/toolchain/parse/testdata/struct/fail_extra_token_in_value.carbon
index 79dbd3aa0f68..bcbd471b51f4 100644
--- a/toolchain/parse/testdata/struct/fail_extra_token_in_value.carbon
+++ b/toolchain/parse/testdata/struct/fail_extra_token_in_value.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/struct/fail_extra_token_in_value.carbon
 
-// CHECK:STDERR: fail_extra_token_in_value.carbon:[[@LINE+3]]:28: error: expected `,` or `}` [UnexpectedTokenAfterListElement]
+// CHECK:STDERR: fail_extra_token_in_value.carbon:[[@LINE+4]]:28: error: expected `,` or `}` [UnexpectedTokenAfterListElement]
 // CHECK:STDERR: var x: {.a: i32} = {.a = 0 banana};
 // CHECK:STDERR:                            ^~~~~~
+// CHECK:STDERR:
 var x: {.a: i32} = {.a = 0 banana};
 
 // CHECK:STDOUT: - filename: fail_extra_token_in_value.carbon
diff --git a/toolchain/parse/testdata/struct/fail_identifier_colon.carbon b/toolchain/parse/testdata/struct/fail_identifier_colon.carbon
index 0bab495e6808..838dcde4b43a 100644
--- a/toolchain/parse/testdata/struct/fail_identifier_colon.carbon
+++ b/toolchain/parse/testdata/struct/fail_identifier_colon.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/struct/fail_identifier_colon.carbon
 
-// CHECK:STDERR: fail_identifier_colon.carbon:[[@LINE+3]]:9: error: expected `.field: field_type` or `.field = value` [ExpectedStructLiteralField]
+// CHECK:STDERR: fail_identifier_colon.carbon:[[@LINE+4]]:9: error: expected `.field: field_type` or `.field = value` [ExpectedStructLiteralField]
 // CHECK:STDERR: var x: {a:} = {};
 // CHECK:STDERR:         ^
+// CHECK:STDERR:
 var x: {a:} = {};
 
 // CHECK:STDOUT: - filename: fail_identifier_colon.carbon
diff --git a/toolchain/parse/testdata/struct/fail_identifier_equals.carbon b/toolchain/parse/testdata/struct/fail_identifier_equals.carbon
index 6394a90f2bec..387d8692b97c 100644
--- a/toolchain/parse/testdata/struct/fail_identifier_equals.carbon
+++ b/toolchain/parse/testdata/struct/fail_identifier_equals.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/struct/fail_identifier_equals.carbon
 
-// CHECK:STDERR: fail_identifier_equals.carbon:[[@LINE+3]]:9: error: expected `.field: field_type` or `.field = value` [ExpectedStructLiteralField]
+// CHECK:STDERR: fail_identifier_equals.carbon:[[@LINE+4]]:9: error: expected `.field: field_type` or `.field = value` [ExpectedStructLiteralField]
 // CHECK:STDERR: var x: {a=} = {};
 // CHECK:STDERR:         ^
+// CHECK:STDERR:
 var x: {a=} = {};
 
 // CHECK:STDOUT: - filename: fail_identifier_equals.carbon
diff --git a/toolchain/parse/testdata/struct/fail_identifier_only.carbon b/toolchain/parse/testdata/struct/fail_identifier_only.carbon
index 1a222956f93e..c8f4d1e49ea2 100644
--- a/toolchain/parse/testdata/struct/fail_identifier_only.carbon
+++ b/toolchain/parse/testdata/struct/fail_identifier_only.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/struct/fail_identifier_only.carbon
 
-// CHECK:STDERR: fail_identifier_only.carbon:[[@LINE+3]]:9: error: expected `.field: field_type` or `.field = value` [ExpectedStructLiteralField]
+// CHECK:STDERR: fail_identifier_only.carbon:[[@LINE+4]]:9: error: expected `.field: field_type` or `.field = value` [ExpectedStructLiteralField]
 // CHECK:STDERR: var x: {a} = {};
 // CHECK:STDERR:         ^
+// CHECK:STDERR:
 var x: {a} = {};
 
 // CHECK:STDOUT: - filename: fail_identifier_only.carbon
diff --git a/toolchain/parse/testdata/struct/fail_invalid_struct_designator.carbon b/toolchain/parse/testdata/struct/fail_invalid_struct_designator.carbon
index bf8e73278358..c74c1798e712 100644
--- a/toolchain/parse/testdata/struct/fail_invalid_struct_designator.carbon
+++ b/toolchain/parse/testdata/struct/fail_invalid_struct_designator.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/struct/fail_invalid_struct_designator.carbon
 
-// CHECK:STDERR: fail_invalid_struct_designator.carbon:[[@LINE+3]]:16: error: expected identifier after `.` [ExpectedIdentifierAfterPeriodOrArrow]
+// CHECK:STDERR: fail_invalid_struct_designator.carbon:[[@LINE+4]]:16: error: expected identifier after `.` [ExpectedIdentifierAfterPeriodOrArrow]
 // CHECK:STDERR: var x: i32 = {.7 = 8};
 // CHECK:STDERR:                ^
+// CHECK:STDERR:
 var x: i32 = {.7 = 8};
 
 // CHECK:STDOUT: - filename: fail_invalid_struct_designator.carbon
diff --git a/toolchain/parse/testdata/struct/fail_missing_type.carbon b/toolchain/parse/testdata/struct/fail_missing_type.carbon
index ef0d709e7b41..bca4a9e4707f 100644
--- a/toolchain/parse/testdata/struct/fail_missing_type.carbon
+++ b/toolchain/parse/testdata/struct/fail_missing_type.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/struct/fail_missing_type.carbon
 
-// CHECK:STDERR: fail_missing_type.carbon:[[@LINE+3]]:12: error: expected expression [ExpectedExpr]
+// CHECK:STDERR: fail_missing_type.carbon:[[@LINE+4]]:12: error: expected expression [ExpectedExpr]
 // CHECK:STDERR: var x: {.a:} = {};
 // CHECK:STDERR:            ^
+// CHECK:STDERR:
 var x: {.a:} = {};
 
 // CHECK:STDOUT: - filename: fail_missing_type.carbon
diff --git a/toolchain/parse/testdata/struct/fail_missing_value.carbon b/toolchain/parse/testdata/struct/fail_missing_value.carbon
index f8ce7b6153f6..bf03b7f1e001 100644
--- a/toolchain/parse/testdata/struct/fail_missing_value.carbon
+++ b/toolchain/parse/testdata/struct/fail_missing_value.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/struct/fail_missing_value.carbon
 
-// CHECK:STDERR: fail_missing_value.carbon:[[@LINE+3]]:12: error: expected expression [ExpectedExpr]
+// CHECK:STDERR: fail_missing_value.carbon:[[@LINE+4]]:12: error: expected expression [ExpectedExpr]
 // CHECK:STDERR: var x: {.a=} = {};
 // CHECK:STDERR:            ^
+// CHECK:STDERR:
 var x: {.a=} = {};
 
 // CHECK:STDOUT: - filename: fail_missing_value.carbon
diff --git a/toolchain/parse/testdata/struct/fail_mix_type_and_value.carbon b/toolchain/parse/testdata/struct/fail_mix_type_and_value.carbon
index 065ea2143dc2..9a94c6ecb3a1 100644
--- a/toolchain/parse/testdata/struct/fail_mix_type_and_value.carbon
+++ b/toolchain/parse/testdata/struct/fail_mix_type_and_value.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/struct/fail_mix_type_and_value.carbon
 
-// CHECK:STDERR: fail_mix_type_and_value.carbon:[[@LINE+3]]:21: error: expected `.field: field_type` [ExpectedStructLiteralField]
+// CHECK:STDERR: fail_mix_type_and_value.carbon:[[@LINE+4]]:21: error: expected `.field: field_type` [ExpectedStructLiteralField]
 // CHECK:STDERR: var x: {.a: i32, .b = 0} = {};
 // CHECK:STDERR:                     ^
+// CHECK:STDERR:
 var x: {.a: i32, .b = 0} = {};
 
 // CHECK:STDOUT: - filename: fail_mix_type_and_value.carbon
diff --git a/toolchain/parse/testdata/struct/fail_mix_value_and_type.carbon b/toolchain/parse/testdata/struct/fail_mix_value_and_type.carbon
index 25bcd3792645..6865024b4be2 100644
--- a/toolchain/parse/testdata/struct/fail_mix_value_and_type.carbon
+++ b/toolchain/parse/testdata/struct/fail_mix_value_and_type.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/struct/fail_mix_value_and_type.carbon
 
-// CHECK:STDERR: fail_mix_value_and_type.carbon:[[@LINE+3]]:17: error: expected `.field = value` [ExpectedStructLiteralField]
+// CHECK:STDERR: fail_mix_value_and_type.carbon:[[@LINE+4]]:17: error: expected `.field = value` [ExpectedStructLiteralField]
 // CHECK:STDERR: var x: {.a = 0, b: i32} = {};
 // CHECK:STDERR:                 ^
+// CHECK:STDERR:
 var x: {.a = 0, b: i32} = {};
 
 // CHECK:STDOUT: - filename: fail_mix_value_and_type.carbon
diff --git a/toolchain/parse/testdata/struct/fail_mix_with_unknown.carbon b/toolchain/parse/testdata/struct/fail_mix_with_unknown.carbon
index 7bdaced29094..2af751c13f42 100644
--- a/toolchain/parse/testdata/struct/fail_mix_with_unknown.carbon
+++ b/toolchain/parse/testdata/struct/fail_mix_with_unknown.carbon
@@ -18,13 +18,14 @@
 // CHECK:STDERR:
 var x: i32 = {.a = 1, .b, .c: i32};
 
-// CHECK:STDERR: fail_mix_with_unknown.carbon:[[@LINE+7]]:26: error: expected `.field: field_type` [ExpectedStructLiteralField]
+// CHECK:STDERR: fail_mix_with_unknown.carbon:[[@LINE+8]]:26: error: expected `.field: field_type` [ExpectedStructLiteralField]
 // CHECK:STDERR: var x: i32 = {.a: i32, .b, .c = 1};
 // CHECK:STDERR:                          ^
 // CHECK:STDERR:
-// CHECK:STDERR: fail_mix_with_unknown.carbon:[[@LINE+3]]:31: error: expected `.field: field_type` [ExpectedStructLiteralField]
+// CHECK:STDERR: fail_mix_with_unknown.carbon:[[@LINE+4]]:31: error: expected `.field: field_type` [ExpectedStructLiteralField]
 // CHECK:STDERR: var x: i32 = {.a: i32, .b, .c = 1};
 // CHECK:STDERR:                               ^
+// CHECK:STDERR:
 var x: i32 = {.a: i32, .b, .c = 1};
 
 // CHECK:STDOUT: - filename: fail_mix_with_unknown.carbon
diff --git a/toolchain/parse/testdata/struct/fail_no_colon_or_equals.carbon b/toolchain/parse/testdata/struct/fail_no_colon_or_equals.carbon
index 732b42731bea..32a1ff904fe5 100644
--- a/toolchain/parse/testdata/struct/fail_no_colon_or_equals.carbon
+++ b/toolchain/parse/testdata/struct/fail_no_colon_or_equals.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/struct/fail_no_colon_or_equals.carbon
 
-// CHECK:STDERR: fail_no_colon_or_equals.carbon:[[@LINE+3]]:11: error: expected `.field: field_type` or `.field = value` [ExpectedStructLiteralField]
+// CHECK:STDERR: fail_no_colon_or_equals.carbon:[[@LINE+4]]:11: error: expected `.field: field_type` or `.field = value` [ExpectedStructLiteralField]
 // CHECK:STDERR: var x: {.a} = {};
 // CHECK:STDERR:           ^
+// CHECK:STDERR:
 var x: {.a} = {};
 
 // CHECK:STDOUT: - filename: fail_no_colon_or_equals.carbon
diff --git a/toolchain/parse/testdata/struct/fail_period_only.carbon b/toolchain/parse/testdata/struct/fail_period_only.carbon
index a1e8cdcb0c0b..a349b02ef6cf 100644
--- a/toolchain/parse/testdata/struct/fail_period_only.carbon
+++ b/toolchain/parse/testdata/struct/fail_period_only.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/struct/fail_period_only.carbon
 
-// CHECK:STDERR: fail_period_only.carbon:[[@LINE+3]]:10: error: expected identifier after `.` [ExpectedIdentifierAfterPeriodOrArrow]
+// CHECK:STDERR: fail_period_only.carbon:[[@LINE+4]]:10: error: expected identifier after `.` [ExpectedIdentifierAfterPeriodOrArrow]
 // CHECK:STDERR: var x: {.} = {};
 // CHECK:STDERR:          ^
+// CHECK:STDERR:
 var x: {.} = {};
 
 // CHECK:STDOUT: - filename: fail_period_only.carbon
diff --git a/toolchain/parse/testdata/struct/fail_period_paren.carbon b/toolchain/parse/testdata/struct/fail_period_paren.carbon
index 7383cb210fee..cf686a58718e 100644
--- a/toolchain/parse/testdata/struct/fail_period_paren.carbon
+++ b/toolchain/parse/testdata/struct/fail_period_paren.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/struct/fail_period_paren.carbon
 
-// CHECK:STDERR: fail_period_paren.carbon:[[@LINE+3]]:10: error: expected identifier after `.` [ExpectedIdentifierAfterPeriodOrArrow]
+// CHECK:STDERR: fail_period_paren.carbon:[[@LINE+4]]:10: error: expected identifier after `.` [ExpectedIdentifierAfterPeriodOrArrow]
 // CHECK:STDERR: var x: {.(a) = 1};
 // CHECK:STDERR:          ^
+// CHECK:STDERR:
 var x: {.(a) = 1};
 
 // CHECK:STDOUT: - filename: fail_period_paren.carbon
diff --git a/toolchain/parse/testdata/struct/fail_period_string_colon.carbon b/toolchain/parse/testdata/struct/fail_period_string_colon.carbon
index b6e9ed9de706..36b6cc1d6340 100644
--- a/toolchain/parse/testdata/struct/fail_period_string_colon.carbon
+++ b/toolchain/parse/testdata/struct/fail_period_string_colon.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/struct/fail_period_string_colon.carbon
 
-// CHECK:STDERR: fail_period_string_colon.carbon:[[@LINE+3]]:10: error: expected identifier after `.` [ExpectedIdentifierAfterPeriodOrArrow]
+// CHECK:STDERR: fail_period_string_colon.carbon:[[@LINE+4]]:10: error: expected identifier after `.` [ExpectedIdentifierAfterPeriodOrArrow]
 // CHECK:STDERR: var x: {."hello": i32, .y: i32} = {};
 // CHECK:STDERR:          ^~~~~~~
+// CHECK:STDERR:
 var x: {."hello": i32, .y: i32} = {};
 
 // CHECK:STDOUT: - filename: fail_period_string_colon.carbon
diff --git a/toolchain/parse/testdata/struct/fail_period_string_equals.carbon b/toolchain/parse/testdata/struct/fail_period_string_equals.carbon
index 02d027ad9bc2..8593144126f6 100644
--- a/toolchain/parse/testdata/struct/fail_period_string_equals.carbon
+++ b/toolchain/parse/testdata/struct/fail_period_string_equals.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/struct/fail_period_string_equals.carbon
 
-// CHECK:STDERR: fail_period_string_equals.carbon:[[@LINE+3]]:10: error: expected identifier after `.` [ExpectedIdentifierAfterPeriodOrArrow]
+// CHECK:STDERR: fail_period_string_equals.carbon:[[@LINE+4]]:10: error: expected identifier after `.` [ExpectedIdentifierAfterPeriodOrArrow]
 // CHECK:STDERR: var x: {."hello" = 0, .y = 4} = {};
 // CHECK:STDERR:          ^~~~~~~
+// CHECK:STDERR:
 var x: {."hello" = 0, .y = 4} = {};
 
 // CHECK:STDOUT: - filename: fail_period_string_equals.carbon
diff --git a/toolchain/parse/testdata/struct/fail_type_no_designator.carbon b/toolchain/parse/testdata/struct/fail_type_no_designator.carbon
index d2146c450169..1d07c17dc80d 100644
--- a/toolchain/parse/testdata/struct/fail_type_no_designator.carbon
+++ b/toolchain/parse/testdata/struct/fail_type_no_designator.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/struct/fail_type_no_designator.carbon
 
-// CHECK:STDERR: fail_type_no_designator.carbon:[[@LINE+3]]:9: error: expected `.field: field_type` or `.field = value` [ExpectedStructLiteralField]
+// CHECK:STDERR: fail_type_no_designator.carbon:[[@LINE+4]]:9: error: expected `.field: field_type` or `.field = value` [ExpectedStructLiteralField]
 // CHECK:STDERR: var x: {i32} = {};
 // CHECK:STDERR:         ^~~
+// CHECK:STDERR:
 var x: {i32} = {};
 
 // CHECK:STDOUT: - filename: fail_type_no_designator.carbon
diff --git a/toolchain/parse/testdata/var/fail_bad_name.carbon b/toolchain/parse/testdata/var/fail_bad_name.carbon
index b790f624686d..faaa2ee85e10 100644
--- a/toolchain/parse/testdata/var/fail_bad_name.carbon
+++ b/toolchain/parse/testdata/var/fail_bad_name.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/var/fail_bad_name.carbon
 
-// CHECK:STDERR: fail_bad_name.carbon:[[@LINE+3]]:5: error: expected name in binding pattern [ExpectedBindingPattern]
+// CHECK:STDERR: fail_bad_name.carbon:[[@LINE+4]]:5: error: expected name in binding pattern [ExpectedBindingPattern]
 // CHECK:STDERR: var *;
 // CHECK:STDERR:     ^
+// CHECK:STDERR:
 var *;
 
 // CHECK:STDOUT: - filename: fail_bad_name.carbon
diff --git a/toolchain/parse/testdata/var/fail_empty.carbon b/toolchain/parse/testdata/var/fail_empty.carbon
index 2a72f4f727e3..c0977bfb2fe6 100644
--- a/toolchain/parse/testdata/var/fail_empty.carbon
+++ b/toolchain/parse/testdata/var/fail_empty.carbon
@@ -8,9 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/var/fail_empty.carbon
 
-// CHECK:STDERR: fail_empty.carbon:[[@LINE+3]]:4: error: expected name in binding pattern [ExpectedBindingPattern]
+// CHECK:STDERR: fail_empty.carbon:[[@LINE+4]]:4: error: expected name in binding pattern [ExpectedBindingPattern]
 // CHECK:STDERR: var;
 // CHECK:STDERR:    ^
+// CHECK:STDERR:
 var;
 
 // CHECK:STDOUT: - filename: fail_empty.carbon
diff --git a/toolchain/parse/testdata/var/fail_no_semi.carbon b/toolchain/parse/testdata/var/fail_no_semi.carbon
index 49d09c4fc41f..1f1ffc049c87 100644
--- a/toolchain/parse/testdata/var/fail_no_semi.carbon
+++ b/toolchain/parse/testdata/var/fail_no_semi.carbon
@@ -10,13 +10,14 @@
 
 var
 
-// CHECK:STDERR: fail_no_semi.carbon:[[@LINE+16]]:21: error: expected name in binding pattern [ExpectedBindingPattern]
+// CHECK:STDERR: fail_no_semi.carbon:[[@LINE+17]]:21: error: expected name in binding pattern [ExpectedBindingPattern]
 // CHECK:STDERR: // CHECK:STDOUT:   ]
 // CHECK:STDERR:                     ^
 // CHECK:STDERR:
-// CHECK:STDERR: fail_no_semi.carbon:[[@LINE+12]]:21: error: `var` declarations must end with a `;` [ExpectedDeclSemi]
+// CHECK:STDERR: fail_no_semi.carbon:[[@LINE+13]]:21: error: `var` declarations must end with a `;` [ExpectedDeclSemi]
 // CHECK:STDERR: // CHECK:STDOUT:   ]
 // CHECK:STDERR:                     ^
+// CHECK:STDERR:
 // CHECK:STDOUT: - filename: fail_no_semi.carbon
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
diff --git a/toolchain/parse/testdata/where_expr/designators.carbon b/toolchain/parse/testdata/where_expr/designators.carbon
index 7dace1a56f05..36996361f1e2 100644
--- a/toolchain/parse/testdata/where_expr/designators.carbon
+++ b/toolchain/parse/testdata/where_expr/designators.carbon
@@ -59,13 +59,14 @@ fn FailStar() {
 
 var x: i32 = .
 
-// CHECK:STDERR: fail_designator_eof.carbon:[[@LINE+93]]:21: error: expected identifier or `Self` after `.` [ExpectedIdentifierOrSelfAfterPeriod]
+// CHECK:STDERR: fail_designator_eof.carbon:[[@LINE+94]]:21: error: expected identifier or `Self` after `.` [ExpectedIdentifierOrSelfAfterPeriod]
 // CHECK:STDERR: // CHECK:STDOUT:   ]
 // CHECK:STDERR:                     ^
 // CHECK:STDERR:
-// CHECK:STDERR: fail_designator_eof.carbon:[[@LINE+89]]:21: error: `var` declarations must end with a `;` [ExpectedDeclSemi]
+// CHECK:STDERR: fail_designator_eof.carbon:[[@LINE+90]]:21: error: `var` declarations must end with a `;` [ExpectedDeclSemi]
 // CHECK:STDERR: // CHECK:STDOUT:   ]
 // CHECK:STDERR:                     ^
+// CHECK:STDERR:
 // CHECK:STDOUT: - filename: designator.carbon
 // CHECK:STDOUT:   parse_tree: [
 // CHECK:STDOUT:     {kind: 'FileStart', text: ''},
diff --git a/toolchain/parse/testdata/where_expr/fail_rewrite.carbon b/toolchain/parse/testdata/where_expr/fail_rewrite.carbon
index 6966676937bb..12dd59cba259 100644
--- a/toolchain/parse/testdata/where_expr/fail_rewrite.carbon
+++ b/toolchain/parse/testdata/where_expr/fail_rewrite.carbon
@@ -61,9 +61,10 @@ fn BinaryOpAfterDesignator(Y:! N where .O + .P = {});
 
 // --- fail_after_and.carbon
 
-// CHECK:STDERR: fail_after_and.carbon:[[@LINE+3]]:43: error: requirement can only use `=` after `.member` designator [RequirementEqualAfterNonDesignator]
+// CHECK:STDERR: fail_after_and.carbon:[[@LINE+4]]:43: error: requirement can only use `=` after `.member` designator [RequirementEqualAfterNonDesignator]
 // CHECK:STDERR: fn AfterAnd(Z:! Q where .R impls S and () = .A);
 // CHECK:STDERR:                                           ^
+// CHECK:STDERR:
 fn AfterAnd(Z:! Q where .R impls S and () = .A);
 
 // CHECK:STDOUT: - filename: fail_not_designator.carbon
diff --git a/toolchain/parse/testdata/where_expr/where_and.carbon b/toolchain/parse/testdata/where_expr/where_and.carbon
index b85a4e35cdee..c447e1ca2f10 100644
--- a/toolchain/parse/testdata/where_expr/where_and.carbon
+++ b/toolchain/parse/testdata/where_expr/where_and.carbon
@@ -32,9 +32,10 @@ fn AndSuffix(Y:! I where .J impls K and);
 
 // --- fail_and_early.carbon
 
-// CHECK:STDERR: fail_and_early.carbon:[[@LINE+3]]:28: error: requirement should use `impls`, `=`, or `==` operator [ExpectedRequirementOperator]
+// CHECK:STDERR: fail_and_early.carbon:[[@LINE+4]]:28: error: requirement should use `impls`, `=`, or `==` operator [ExpectedRequirementOperator]
 // CHECK:STDERR: fn AndEarly(Z:! L where .M and N);
 // CHECK:STDERR:                            ^~~
+// CHECK:STDERR:
 fn AndEarly(Z:! L where .M and N);
 
 // CHECK:STDOUT: - filename: success.carbon
diff --git a/toolchain/parse/testdata/while/fail_missing_cond.carbon b/toolchain/parse/testdata/while/fail_missing_cond.carbon
index 9d499564339d..851e803623b1 100644
--- a/toolchain/parse/testdata/while/fail_missing_cond.carbon
+++ b/toolchain/parse/testdata/while/fail_missing_cond.carbon
@@ -9,9 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/while/fail_missing_cond.carbon
 
 fn F() {
-  // CHECK:STDERR: fail_missing_cond.carbon:[[@LINE+3]]:9: error: expected `(` after `while` [ExpectedParenAfter]
+  // CHECK:STDERR: fail_missing_cond.carbon:[[@LINE+4]]:9: error: expected `(` after `while` [ExpectedParenAfter]
   // CHECK:STDERR:   while {
   // CHECK:STDERR:         ^
+  // CHECK:STDERR:
   while {
   }
 }
diff --git a/toolchain/parse/testdata/while/fail_no_semi.carbon b/toolchain/parse/testdata/while/fail_no_semi.carbon
index 59a017d7aa24..1480b7e0a100 100644
--- a/toolchain/parse/testdata/while/fail_no_semi.carbon
+++ b/toolchain/parse/testdata/while/fail_no_semi.carbon
@@ -19,9 +19,10 @@ fn F() {
     }
     if (c) {
       continue
-    // CHECK:STDERR: fail_no_semi.carbon:[[@LINE+3]]:5: error: `continue` statements must end with a `;` [ExpectedStatementSemi]
+    // CHECK:STDERR: fail_no_semi.carbon:[[@LINE+4]]:5: error: `continue` statements must end with a `;` [ExpectedStatementSemi]
     // CHECK:STDERR:     }
     // CHECK:STDERR:     ^
+    // CHECK:STDERR:
     }
   }
 }
diff --git a/toolchain/parse/testdata/while/fail_unbraced.carbon b/toolchain/parse/testdata/while/fail_unbraced.carbon
index adc014f7f192..c19903aa9087 100644
--- a/toolchain/parse/testdata/while/fail_unbraced.carbon
+++ b/toolchain/parse/testdata/while/fail_unbraced.carbon
@@ -11,9 +11,10 @@
 
 fn F() {
   while (a)
-    // CHECK:STDERR: fail_unbraced.carbon:[[@LINE+3]]:5: error: expected braced code block [ExpectedCodeBlock]
+    // CHECK:STDERR: fail_unbraced.carbon:[[@LINE+4]]:5: error: expected braced code block [ExpectedCodeBlock]
     // CHECK:STDERR:     break;
     // CHECK:STDERR:     ^~~~~
+    // CHECK:STDERR:
     break;
 }
 
diff --git a/toolchain/testing/file_test.cpp b/toolchain/testing/file_test.cpp
index 60279793483f..83b0d2a8d0c5 100644
--- a/toolchain/testing/file_test.cpp
+++ b/toolchain/testing/file_test.cpp
@@ -46,6 +46,13 @@ class ToolchainFileTest : public FileTestBase {
 
     Driver driver(fs, &installation_, stdout, stderr);
     auto driver_result = driver.RunCommand(test_args);
+    // If any diagnostics have been produced, add a trailing newline to make the
+    // last diagnostic match intermediate diagnostics (that have a newline
+    // separator between them). This reduces churn when adding new diagnostics
+    // to test cases.
+    if (stderr.tell() > 0) {
+      stderr << '\n';
+    }
 
     RunResult result{
         .success = driver_result.success,