From d0e067ac7586bfcf29c05adfe4b68c9952d4ac67 Mon Sep 17 00:00:00 2001
From: Richard Smith <richard@metafoo.co.uk>
Date: Mon, 2 Dec 2024 10:49:30 -0800
Subject: [PATCH] Fix impl lookup to look in the arguments of a specific.
 (#4601)

---
 toolchain/check/impl_lookup.cpp               |  25 +-
 .../impl/lookup/no_prelude/import.carbon      |  34 +-
 .../lookup/no_prelude/specific_args.carbon    | 806 ++++++++++++++++++
 3 files changed, 850 insertions(+), 15 deletions(-)
 create mode 100644 toolchain/check/testdata/impl/lookup/no_prelude/specific_args.carbon

diff --git a/toolchain/check/impl_lookup.cpp b/toolchain/check/impl_lookup.cpp
index 1320d104e3d5..43743303aaa1 100644
--- a/toolchain/check/impl_lookup.cpp
+++ b/toolchain/check/impl_lookup.cpp
@@ -36,6 +36,21 @@ static auto FindAssociatedImportIRs(Context& context,
   worklist.push_back(context.constant_values().GetInstId(type_const_id));
   worklist.push_back(context.constant_values().GetInstId(interface_const_id));
 
+  // Push the contents of an instruction block onto our worklist.
+  auto push_block = [&](SemIR::InstBlockId block_id) {
+    if (block_id.is_valid()) {
+      auto block = context.inst_blocks().Get(block_id);
+      worklist.append(block.begin(), block.end());
+    }
+  };
+
+  // Add the arguments of a specific to the worklist.
+  auto push_args = [&](SemIR::SpecificId specific_id) {
+    if (specific_id.is_valid()) {
+      push_block(context.specifics().Get(specific_id).args_id);
+    }
+  };
+
   while (!worklist.empty()) {
     auto inst_id = worklist.pop_back_val();
 
@@ -52,10 +67,7 @@ static auto FindAssociatedImportIRs(Context& context,
           break;
         }
         case SemIR::IdKind::For<SemIR::InstBlockId>: {
-          if (auto id = SemIR::InstBlockId(arg); id.is_valid()) {
-            auto block = context.inst_blocks().Get(id);
-            worklist.append(block.begin(), block.end());
-          }
+          push_block(SemIR::InstBlockId(arg));
           break;
         }
         case SemIR::IdKind::For<SemIR::ClassId>: {
@@ -71,6 +83,7 @@ static auto FindAssociatedImportIRs(Context& context,
               context.facet_types().Get(SemIR::FacetTypeId(arg));
           for (const auto& impl : facet_type_info.impls_constraints) {
             add_entity(context.interfaces().Get(impl.interface_id));
+            push_args(impl.specific_id);
           }
           break;
         }
@@ -78,6 +91,10 @@ static auto FindAssociatedImportIRs(Context& context,
           add_entity(context.functions().Get(SemIR::FunctionId(arg)));
           break;
         }
+        case SemIR::IdKind::For<SemIR::SpecificId>: {
+          push_args(SemIR::SpecificId(arg));
+          break;
+        }
         default: {
           break;
         }
diff --git a/toolchain/check/testdata/impl/lookup/no_prelude/import.carbon b/toolchain/check/testdata/impl/lookup/no_prelude/import.carbon
index 7e6b1505a681..db884895d7fb 100644
--- a/toolchain/check/testdata/impl/lookup/no_prelude/import.carbon
+++ b/toolchain/check/testdata/impl/lookup/no_prelude/import.carbon
@@ -142,7 +142,7 @@ fn L() {
   obj.(PackageHasParam.Y.K)();
 }
 
-// --- fail_todo_use_generic_interface_as_param.carbon
+// --- use_generic_interface_as_param.carbon
 
 library "[[@TEST_NAME]]";
 
@@ -152,10 +152,6 @@ import PackageGenericInterface;
 fn M() {
   var obj: PackageHasParam.AnyParam(
     PackageGenericInterface.GenericInterface) = {};
-  // CHECK:STDERR: fail_todo_use_generic_interface_as_param.carbon:[[@LINE+4]]:3: error: cannot access member of interface `Y` in type `AnyParam(<cannot stringify inst+38 kind StructValue>)` that does not implement that interface [MissingImplInMemberAccess]
-  // CHECK:STDERR:   obj.(PackageHasParam.Y.K)();
-  // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~~~~~~~
-  // CHECK:STDERR:
   obj.(PackageHasParam.Y.K)();
 }
 
@@ -1344,10 +1340,11 @@ fn Test(c: HasExtraInterfaces.C(type)) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @K.2(constants.%.3) {}
 // CHECK:STDOUT:
-// CHECK:STDOUT: --- fail_todo_use_generic_interface_as_param.carbon
+// CHECK:STDOUT: --- use_generic_interface_as_param.carbon
 // CHECK:STDOUT:
 // CHECK:STDOUT: constants {
 // CHECK:STDOUT:   %M.type: type = fn_type @M [template]
+// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [template]
 // CHECK:STDOUT:   %M: %M.type = struct_value () [template]
 // CHECK:STDOUT:   %AnyParam.type: type = generic_class_type @AnyParam [template]
 // CHECK:STDOUT:   %AnyParam.1: %AnyParam.type = struct_value () [template]
@@ -1368,9 +1365,12 @@ fn Test(c: HasExtraInterfaces.C(type)) {
 // CHECK:STDOUT:   %struct: %AnyParam.3 = struct_value () [template]
 // CHECK:STDOUT:   %Y.type: type = facet_type <@Y> [template]
 // CHECK:STDOUT:   %Self.3: %Y.type = bind_symbolic_name Self, 0 [symbolic]
-// CHECK:STDOUT:   %K.type: type = fn_type @K [template]
-// CHECK:STDOUT:   %.4: type = assoc_entity_type %Y.type, %K.type [template]
+// CHECK:STDOUT:   %K.type.1: type = fn_type @K.1 [template]
+// CHECK:STDOUT:   %.4: type = assoc_entity_type %Y.type, %K.type.1 [template]
 // CHECK:STDOUT:   %.5: %.4 = assoc_entity element0, imports.%import_ref.10 [template]
+// CHECK:STDOUT:   %K.type.2: type = fn_type @K.2 [template]
+// CHECK:STDOUT:   %K.2: %K.type.2 = struct_value () [template]
+// CHECK:STDOUT:   %.6: <witness> = interface_witness (%K.2) [template]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: imports {
@@ -1392,6 +1392,9 @@ fn Test(c: HasExtraInterfaces.C(type)) {
 // CHECK:STDOUT:   %import_ref.7 = import_ref PackageHasParam//default, inst+28, unloaded
 // CHECK:STDOUT:   %import_ref.8: %.4 = import_ref PackageHasParam//default, inst+34, loaded [template = constants.%.5]
 // CHECK:STDOUT:   %import_ref.9 = import_ref PackageHasParam//default, inst+30, unloaded
+// CHECK:STDOUT:   %import_ref.11: type = import_ref PackageGenericInterface//default, inst+46, loaded [template = constants.%AnyParam.3]
+// CHECK:STDOUT:   %import_ref.12: type = import_ref PackageGenericInterface//default, inst+56, loaded [template = constants.%Y.type]
+// CHECK:STDOUT:   %import_ref.13: <witness> = import_ref PackageGenericInterface//default, inst+65, loaded [template = constants.%.6]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
@@ -1427,6 +1430,11 @@ fn Test(c: HasExtraInterfaces.C(type)) {
 // CHECK:STDOUT:   witness = (imports.%import_ref.9)
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl: imports.%import_ref.11 as imports.%import_ref.12 {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   witness = imports.%import_ref.13
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
 // CHECK:STDOUT: generic class @AnyParam(constants.%T: type, constants.%X.2: @AnyParam.%T (%T)) {
 // CHECK:STDOUT:   %T: type = bind_symbolic_name T, 0 [symbolic = %T (constants.%T)]
 // CHECK:STDOUT:   %T.patt: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt (constants.%T.patt)]
@@ -1456,18 +1464,22 @@ fn Test(c: HasExtraInterfaces.C(type)) {
 // CHECK:STDOUT:   %.loc9_51: init %AnyParam.3 = converted %.loc9_50.1, %.loc9_50.2 [template = constants.%struct]
 // CHECK:STDOUT:   assign %obj.var, %.loc9_51
 // CHECK:STDOUT:   %obj.ref: ref %AnyParam.3 = name_ref obj, %obj
-// CHECK:STDOUT:   %PackageHasParam.ref.loc14: <namespace> = name_ref PackageHasParam, imports.%PackageHasParam [template = imports.%PackageHasParam]
+// CHECK:STDOUT:   %PackageHasParam.ref.loc10: <namespace> = name_ref PackageHasParam, imports.%PackageHasParam [template = imports.%PackageHasParam]
 // CHECK:STDOUT:   %Y.ref: type = name_ref Y, imports.%import_ref.6 [template = constants.%Y.type]
 // CHECK:STDOUT:   %K.ref: %.4 = name_ref K, imports.%import_ref.8 [template = constants.%.5]
+// CHECK:STDOUT:   %.loc10: %K.type.1 = interface_witness_access constants.%.6, element0 [template = constants.%K.2]
+// CHECK:STDOUT:   %K.call: init %empty_tuple.type = call %.loc10()
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: generic fn @K(constants.%Self.3: %Y.type) {
+// CHECK:STDOUT: generic fn @K.1(constants.%Self.3: %Y.type) {
 // CHECK:STDOUT: !definition:
 // CHECK:STDOUT:
 // CHECK:STDOUT:   fn();
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
+// CHECK:STDOUT: fn @K.2();
+// CHECK:STDOUT:
 // CHECK:STDOUT: specific @AnyParam(constants.%T, constants.%X.1) {
 // CHECK:STDOUT:   %T => constants.%T
 // CHECK:STDOUT:   %T.patt => constants.%T
@@ -1501,7 +1513,7 @@ fn Test(c: HasExtraInterfaces.C(type)) {
 // CHECK:STDOUT: !definition:
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: specific @K(constants.%Self.3) {}
+// CHECK:STDOUT: specific @K.1(constants.%Self.3) {}
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- has_extra_interfaces.carbon
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/impl/lookup/no_prelude/specific_args.carbon b/toolchain/check/testdata/impl/lookup/no_prelude/specific_args.carbon
new file mode 100644
index 000000000000..00dd56c909b2
--- /dev/null
+++ b/toolchain/check/testdata/impl/lookup/no_prelude/specific_args.carbon
@@ -0,0 +1,806 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// AUTOUPDATE
+// TIP: To test this file alone, run:
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/lookup/no_prelude/specific_args.carbon
+// TIP: To dump output, run:
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/lookup/no_prelude/specific_args.carbon
+
+// --- types.carbon
+
+library "[[@TEST_NAME]]";
+
+interface I(T:! type) { fn F(); }
+class C(T:! type) {}
+
+class X {}
+
+// --- impl_in_interface_args.carbon
+
+library "[[@TEST_NAME]]";
+import library "types";
+
+class InInterfaceArgs {}
+
+impl X as I(InInterfaceArgs) { fn F() {} }
+
+// --- use_impl_in_interface_args.carbon
+
+library "[[@TEST_NAME]]";
+import library "types";
+import library "impl_in_interface_args";
+
+fn G(x: X) { x.(I(InInterfaceArgs).F)(); }
+
+// --- impl_in_class_args.carbon
+
+library "[[@TEST_NAME]]";
+import library "types";
+
+class InClassArgs {}
+
+impl C(InClassArgs) as I(X) { fn F() {} }
+
+// --- use_impl_in_class_args.carbon
+
+library "[[@TEST_NAME]]";
+import library "types";
+import library "impl_in_class_args";
+
+fn H(c: C(InClassArgs)) { c.(I(X).F)(); }
+
+// CHECK:STDOUT: --- types.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %T: type = bind_symbolic_name T, 0 [symbolic]
+// CHECK:STDOUT:   %T.patt: type = symbolic_binding_pattern T, 0 [symbolic]
+// CHECK:STDOUT:   %I.type.1: type = generic_interface_type @I [template]
+// CHECK:STDOUT:   %I: %I.type.1 = struct_value () [template]
+// CHECK:STDOUT:   %I.type.2: type = facet_type <@I, @I(%T)> [symbolic]
+// CHECK:STDOUT:   %Self: %I.type.2 = bind_symbolic_name Self, 1 [symbolic]
+// CHECK:STDOUT:   %F.type: type = fn_type @F, @I(%T) [symbolic]
+// CHECK:STDOUT:   %F: %F.type = struct_value () [symbolic]
+// CHECK:STDOUT:   %.1: type = assoc_entity_type %I.type.2, %F.type [symbolic]
+// CHECK:STDOUT:   %.2: %.1 = assoc_entity element0, @I.%F.decl [symbolic]
+// CHECK:STDOUT:   %C.type: type = generic_class_type @C [template]
+// CHECK:STDOUT:   %C.1: %C.type = struct_value () [template]
+// CHECK:STDOUT:   %C.2: type = class_type @C, @C(%T) [symbolic]
+// CHECK:STDOUT:   %.3: type = struct_type {} [template]
+// CHECK:STDOUT:   %.4: <witness> = complete_type_witness %.3 [template]
+// CHECK:STDOUT:   %X: type = class_type @X [template]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [template] {
+// CHECK:STDOUT:     .I = %I.decl
+// CHECK:STDOUT:     .C = %C.decl
+// CHECK:STDOUT:     .X = %X.decl
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %I.decl: %I.type.1 = interface_decl @I [template = constants.%I] {
+// CHECK:STDOUT:     %T.patt.loc4_13.1: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc4_13.2 (constants.%T.patt)]
+// CHECK:STDOUT:     %T.param_patt: type = value_param_pattern %T.patt.loc4_13.1, runtime_param<invalid> [symbolic = %T.patt.loc4_13.2 (constants.%T.patt)]
+// CHECK:STDOUT:   } {
+// CHECK:STDOUT:     %T.param: type = value_param runtime_param<invalid>
+// CHECK:STDOUT:     %T.loc4_13.1: type = bind_symbolic_name T, 0, %T.param [symbolic = %T.loc4_13.2 (constants.%T)]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %C.decl: %C.type = class_decl @C [template = constants.%C.1] {
+// CHECK:STDOUT:     %T.patt.loc5_9.1: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc5_9.2 (constants.%T.patt)]
+// CHECK:STDOUT:     %T.param_patt: type = value_param_pattern %T.patt.loc5_9.1, runtime_param<invalid> [symbolic = %T.patt.loc5_9.2 (constants.%T.patt)]
+// CHECK:STDOUT:   } {
+// CHECK:STDOUT:     %T.param: type = value_param runtime_param<invalid>
+// CHECK:STDOUT:     %T.loc5_9.1: type = bind_symbolic_name T, 0, %T.param [symbolic = %T.loc5_9.2 (constants.%T)]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %X.decl: type = class_decl @X [template = constants.%X] {} {}
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic interface @I(%T.loc4_13.1: type) {
+// CHECK:STDOUT:   %T.loc4_13.2: type = bind_symbolic_name T, 0 [symbolic = %T.loc4_13.2 (constants.%T)]
+// CHECK:STDOUT:   %T.patt.loc4_13.2: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc4_13.2 (constants.%T.patt)]
+// CHECK:STDOUT:
+// CHECK:STDOUT: !definition:
+// CHECK:STDOUT:   %I.type: type = facet_type <@I, @I(%T.loc4_13.2)> [symbolic = %I.type (constants.%I.type.2)]
+// CHECK:STDOUT:   %Self.2: %I.type.2 = bind_symbolic_name Self, 1 [symbolic = %Self.2 (constants.%Self)]
+// CHECK:STDOUT:   %F.type: type = fn_type @F, @I(%T.loc4_13.2) [symbolic = %F.type (constants.%F.type)]
+// CHECK:STDOUT:   %F: @I.%F.type (%F.type) = struct_value () [symbolic = %F (constants.%F)]
+// CHECK:STDOUT:   %.loc4_31.2: type = assoc_entity_type @I.%I.type (%I.type.2), @I.%F.type (%F.type) [symbolic = %.loc4_31.2 (constants.%.1)]
+// CHECK:STDOUT:   %.loc4_31.3: @I.%.loc4_31.2 (%.1) = assoc_entity element0, %F.decl [symbolic = %.loc4_31.3 (constants.%.2)]
+// CHECK:STDOUT:
+// CHECK:STDOUT:   interface {
+// CHECK:STDOUT:     %Self.1: @I.%I.type (%I.type.2) = bind_symbolic_name Self, 1 [symbolic = %Self.2 (constants.%Self)]
+// CHECK:STDOUT:     %F.decl: @I.%F.type (%F.type) = fn_decl @F [symbolic = @I.%F (constants.%F)] {} {}
+// CHECK:STDOUT:     %.loc4_31.1: @I.%.loc4_31.2 (%.1) = assoc_entity element0, %F.decl [symbolic = %.loc4_31.3 (constants.%.2)]
+// CHECK:STDOUT:
+// CHECK:STDOUT:   !members:
+// CHECK:STDOUT:     .Self = %Self.1
+// CHECK:STDOUT:     .F = %.loc4_31.1
+// CHECK:STDOUT:     witness = (%F.decl)
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic class @C(%T.loc5_9.1: type) {
+// CHECK:STDOUT:   %T.loc5_9.2: type = bind_symbolic_name T, 0 [symbolic = %T.loc5_9.2 (constants.%T)]
+// CHECK:STDOUT:   %T.patt.loc5_9.2: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc5_9.2 (constants.%T.patt)]
+// CHECK:STDOUT:
+// CHECK:STDOUT: !definition:
+// CHECK:STDOUT:
+// CHECK:STDOUT:   class {
+// CHECK:STDOUT:     %.loc5: <witness> = complete_type_witness %.3 [template = constants.%.4]
+// CHECK:STDOUT:
+// CHECK:STDOUT:   !members:
+// CHECK:STDOUT:     .Self = constants.%C.2
+// CHECK:STDOUT:     complete_type_witness = %.loc5
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @X {
+// CHECK:STDOUT:   %.loc7: <witness> = complete_type_witness %.3 [template = constants.%.4]
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%X
+// CHECK:STDOUT:   complete_type_witness = %.loc7
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic fn @F(@I.%T.loc4_13.1: type, @I.%Self.1: @I.%I.type (%I.type.2)) {
+// CHECK:STDOUT:
+// CHECK:STDOUT:   fn();
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @I(constants.%T) {
+// CHECK:STDOUT:   %T.loc4_13.2 => constants.%T
+// CHECK:STDOUT:   %T.patt.loc4_13.2 => constants.%T
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @F(constants.%T, constants.%Self) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @I(%T.loc4_13.2) {
+// CHECK:STDOUT:   %T.loc4_13.2 => constants.%T
+// CHECK:STDOUT:   %T.patt.loc4_13.2 => constants.%T
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @C(constants.%T) {
+// CHECK:STDOUT:   %T.loc5_9.2 => constants.%T
+// CHECK:STDOUT:   %T.patt.loc5_9.2 => constants.%T
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- impl_in_interface_args.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %InInterfaceArgs: type = class_type @InInterfaceArgs [template]
+// CHECK:STDOUT:   %.1: type = struct_type {} [template]
+// CHECK:STDOUT:   %.2: <witness> = complete_type_witness %.1 [template]
+// CHECK:STDOUT:   %X: type = class_type @X [template]
+// CHECK:STDOUT:   %I.type.1: type = generic_interface_type @I [template]
+// CHECK:STDOUT:   %I: %I.type.1 = struct_value () [template]
+// CHECK:STDOUT:   %T: type = bind_symbolic_name T, 0 [symbolic]
+// CHECK:STDOUT:   %I.type.2: type = facet_type <@I, @I(%T)> [symbolic]
+// CHECK:STDOUT:   %Self.1: @I.%I.type (%I.type.2) = bind_symbolic_name Self, 1 [symbolic]
+// CHECK:STDOUT:   %T.patt: type = symbolic_binding_pattern T, 0 [symbolic]
+// CHECK:STDOUT:   %Self.2: %I.type.2 = bind_symbolic_name Self, 1 [symbolic]
+// CHECK:STDOUT:   %F.type.1: type = fn_type @F.1, @I(%T) [symbolic]
+// CHECK:STDOUT:   %F.1: %F.type.1 = struct_value () [symbolic]
+// CHECK:STDOUT:   %.3: type = assoc_entity_type %I.type.2, %F.type.1 [symbolic]
+// CHECK:STDOUT:   %.4: %.3 = assoc_entity element0, imports.%import_ref.9 [symbolic]
+// CHECK:STDOUT:   %I.type.3: type = facet_type <@I, @I(%InInterfaceArgs)> [template]
+// CHECK:STDOUT:   %F.type.2: type = fn_type @F.2 [template]
+// CHECK:STDOUT:   %F.2: %F.type.2 = struct_value () [template]
+// CHECK:STDOUT:   %F.type.3: type = fn_type @F.1, @I(%InInterfaceArgs) [template]
+// CHECK:STDOUT:   %F.3: %F.type.3 = struct_value () [template]
+// CHECK:STDOUT:   %.5: type = assoc_entity_type %I.type.3, %F.type.3 [template]
+// CHECK:STDOUT:   %.6: %.5 = assoc_entity element0, imports.%import_ref.9 [template]
+// CHECK:STDOUT:   %.7: %I.type.2 = facet_value %X, %X [symbolic]
+// CHECK:STDOUT:   %.8: <witness> = interface_witness (%F.2) [template]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: imports {
+// CHECK:STDOUT:   %import_ref.1: %I.type.1 = import_ref Main//types, inst+7, loaded [template = constants.%I]
+// CHECK:STDOUT:   %import_ref.2 = import_ref Main//types, inst+32, unloaded
+// CHECK:STDOUT:   %import_ref.3: type = import_ref Main//types, inst+41, loaded [template = constants.%X]
+// CHECK:STDOUT:   %import_ref.4: <witness> = import_ref Main//types, inst+43, loaded [template = constants.%.2]
+// CHECK:STDOUT:   %import_ref.5 = import_ref Main//types, inst+42, unloaded
+// CHECK:STDOUT:   %import_ref.6 = import_ref Main//types, inst+14, unloaded
+// CHECK:STDOUT:   %import_ref.7 = import_ref Main//types, inst+20, unloaded
+// CHECK:STDOUT:   %import_ref.8: @I.%F.type (%F.type.1) = import_ref Main//types, inst+16, loaded [symbolic = @I.%F (constants.%F.1)]
+// CHECK:STDOUT:   %import_ref.9 = import_ref Main//types, inst+16, unloaded
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [template] {
+// CHECK:STDOUT:     .I = imports.%import_ref.1
+// CHECK:STDOUT:     .C = imports.%import_ref.2
+// CHECK:STDOUT:     .X = imports.%import_ref.3
+// CHECK:STDOUT:     .InInterfaceArgs = %InInterfaceArgs.decl
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %default.import = import <invalid>
+// CHECK:STDOUT:   %InInterfaceArgs.decl: type = class_decl @InInterfaceArgs [template = constants.%InInterfaceArgs] {} {}
+// CHECK:STDOUT:   impl_decl @impl [template] {} {
+// CHECK:STDOUT:     %X.ref: type = name_ref X, imports.%import_ref.3 [template = constants.%X]
+// CHECK:STDOUT:     %I.ref: %I.type.1 = name_ref I, imports.%import_ref.1 [template = constants.%I]
+// CHECK:STDOUT:     %InInterfaceArgs.ref: type = name_ref InInterfaceArgs, file.%InInterfaceArgs.decl [template = constants.%InInterfaceArgs]
+// CHECK:STDOUT:     %I.type: type = facet_type <@I, @I(constants.%InInterfaceArgs)> [template = constants.%I.type.3]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic interface @I(constants.%T: type) {
+// CHECK:STDOUT:   %T: type = bind_symbolic_name T, 0 [symbolic = %T (constants.%T)]
+// CHECK:STDOUT:   %T.patt: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt (constants.%T.patt)]
+// CHECK:STDOUT:
+// CHECK:STDOUT: !definition:
+// CHECK:STDOUT:   %I.type: type = facet_type <@I, @I(%T)> [symbolic = %I.type (constants.%I.type.2)]
+// CHECK:STDOUT:   %Self: %I.type.2 = bind_symbolic_name Self, 1 [symbolic = %Self (constants.%Self.2)]
+// CHECK:STDOUT:   %F.type: type = fn_type @F.1, @I(%T) [symbolic = %F.type (constants.%F.type.1)]
+// CHECK:STDOUT:   %F: @I.%F.type (%F.type.1) = struct_value () [symbolic = %F (constants.%F.1)]
+// CHECK:STDOUT:   %.1: type = assoc_entity_type @I.%I.type (%I.type.2), @I.%F.type (%F.type.1) [symbolic = %.1 (constants.%.3)]
+// CHECK:STDOUT:   %.2: @I.%.1 (%.3) = assoc_entity element0, imports.%import_ref.9 [symbolic = %.2 (constants.%.4)]
+// CHECK:STDOUT:
+// CHECK:STDOUT:   interface {
+// CHECK:STDOUT:   !members:
+// CHECK:STDOUT:     .Self = imports.%import_ref.6
+// CHECK:STDOUT:     .F = imports.%import_ref.7
+// CHECK:STDOUT:     witness = (imports.%import_ref.8)
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl: %X.ref as %I.type {
+// CHECK:STDOUT:   %F.decl: %F.type.2 = fn_decl @F.2 [template = constants.%F.2] {} {}
+// CHECK:STDOUT:   %.loc7: <witness> = interface_witness (%F.decl) [template = constants.%.8]
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .F = %F.decl
+// CHECK:STDOUT:   witness = %.loc7
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @InInterfaceArgs {
+// CHECK:STDOUT:   %.loc5: <witness> = complete_type_witness %.1 [template = constants.%.2]
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%InInterfaceArgs
+// CHECK:STDOUT:   complete_type_witness = %.loc5
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @X {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = imports.%import_ref.5
+// CHECK:STDOUT:   complete_type_witness = imports.%import_ref.4
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic fn @F.1(constants.%T: type, constants.%Self.1: @I.%I.type (%I.type.2)) {
+// CHECK:STDOUT:
+// CHECK:STDOUT:   fn();
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @F.2() {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   return
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @I(constants.%T) {
+// CHECK:STDOUT:   %T => constants.%T
+// CHECK:STDOUT:   %T.patt => constants.%T
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @I(%T) {
+// CHECK:STDOUT:   %T => constants.%T
+// CHECK:STDOUT:   %T.patt => constants.%T
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @F.1(constants.%T, constants.%Self.1) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @I(constants.%InInterfaceArgs) {
+// CHECK:STDOUT:   %T => constants.%InInterfaceArgs
+// CHECK:STDOUT:   %T.patt => constants.%InInterfaceArgs
+// CHECK:STDOUT:
+// CHECK:STDOUT: !definition:
+// CHECK:STDOUT:   %I.type => constants.%I.type.3
+// CHECK:STDOUT:   %Self => constants.%Self.2
+// CHECK:STDOUT:   %F.type => constants.%F.type.3
+// CHECK:STDOUT:   %F => constants.%F.3
+// CHECK:STDOUT:   %.1 => constants.%.5
+// CHECK:STDOUT:   %.2 => constants.%.6
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @F.1(constants.%InInterfaceArgs, constants.%.7) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- use_impl_in_interface_args.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %X: type = class_type @X [template]
+// CHECK:STDOUT:   %.1: type = struct_type {} [template]
+// CHECK:STDOUT:   %.2: <witness> = complete_type_witness %.1 [template]
+// CHECK:STDOUT:   %G.type: type = fn_type @G [template]
+// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [template]
+// CHECK:STDOUT:   %G: %G.type = struct_value () [template]
+// CHECK:STDOUT:   %I.type.1: type = generic_interface_type @I [template]
+// CHECK:STDOUT:   %I: %I.type.1 = struct_value () [template]
+// CHECK:STDOUT:   %T: type = bind_symbolic_name T, 0 [symbolic]
+// CHECK:STDOUT:   %I.type.2: type = facet_type <@I, @I(%T)> [symbolic]
+// CHECK:STDOUT:   %Self.1: @I.%I.type (%I.type.2) = bind_symbolic_name Self, 1 [symbolic]
+// CHECK:STDOUT:   %T.patt: type = symbolic_binding_pattern T, 0 [symbolic]
+// CHECK:STDOUT:   %Self.2: %I.type.2 = bind_symbolic_name Self, 1 [symbolic]
+// CHECK:STDOUT:   %F.type.1: type = fn_type @F.1, @I(%T) [symbolic]
+// CHECK:STDOUT:   %F.1: %F.type.1 = struct_value () [symbolic]
+// CHECK:STDOUT:   %.4: type = assoc_entity_type %I.type.2, %F.type.1 [symbolic]
+// CHECK:STDOUT:   %.5: %.4 = assoc_entity element0, imports.%import_ref.10 [symbolic]
+// CHECK:STDOUT:   %InInterfaceArgs: type = class_type @InInterfaceArgs [template]
+// CHECK:STDOUT:   %I.type.3: type = facet_type <@I, @I(%InInterfaceArgs)> [template]
+// CHECK:STDOUT:   %F.type.2: type = fn_type @F.1, @I(%InInterfaceArgs) [template]
+// CHECK:STDOUT:   %F.2: %F.type.2 = struct_value () [template]
+// CHECK:STDOUT:   %.6: type = assoc_entity_type %I.type.3, %F.type.2 [template]
+// CHECK:STDOUT:   %.7: %.6 = assoc_entity element0, imports.%import_ref.10 [template]
+// CHECK:STDOUT:   %.8: %.4 = assoc_entity element0, imports.%import_ref.13 [symbolic]
+// CHECK:STDOUT:   %F.type.3: type = fn_type @F.2 [template]
+// CHECK:STDOUT:   %F.3: %F.type.3 = struct_value () [template]
+// CHECK:STDOUT:   %.9: <witness> = interface_witness (%F.3) [template]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: imports {
+// CHECK:STDOUT:   %import_ref.1: %I.type.1 = import_ref Main//types, inst+7, loaded [template = constants.%I]
+// CHECK:STDOUT:   %import_ref.2 = import_ref Main//types, inst+32, unloaded
+// CHECK:STDOUT:   %import_ref.3: type = import_ref Main//types, inst+41, loaded [template = constants.%X]
+// CHECK:STDOUT:   %import_ref.4: type = import_ref Main//impl_in_interface_args, inst+5, loaded [template = constants.%InInterfaceArgs]
+// CHECK:STDOUT:   %import_ref.5: <witness> = import_ref Main//types, inst+43, loaded [template = constants.%.2]
+// CHECK:STDOUT:   %import_ref.6 = import_ref Main//types, inst+42, unloaded
+// CHECK:STDOUT:   %import_ref.7 = import_ref Main//types, inst+14, unloaded
+// CHECK:STDOUT:   %import_ref.8: @I.%.1 (%.4) = import_ref Main//types, inst+20, loaded [symbolic = @I.%.2 (constants.%.8)]
+// CHECK:STDOUT:   %import_ref.9 = import_ref Main//types, inst+16, unloaded
+// CHECK:STDOUT:   %import_ref.10 = import_ref Main//types, inst+16, unloaded
+// CHECK:STDOUT:   %import_ref.11: <witness> = import_ref Main//impl_in_interface_args, inst+8, loaded [template = constants.%.2]
+// CHECK:STDOUT:   %import_ref.12 = import_ref Main//impl_in_interface_args, inst+6, unloaded
+// CHECK:STDOUT:   %import_ref.14: type = import_ref Main//impl_in_interface_args, inst+14, loaded [template = constants.%X]
+// CHECK:STDOUT:   %import_ref.15: type = import_ref Main//impl_in_interface_args, inst+45, loaded [template = constants.%I.type.3]
+// CHECK:STDOUT:   %import_ref.16: <witness> = import_ref Main//impl_in_interface_args, inst+56, loaded [template = constants.%.9]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [template] {
+// CHECK:STDOUT:     .I = imports.%import_ref.1
+// CHECK:STDOUT:     .C = imports.%import_ref.2
+// CHECK:STDOUT:     .X = imports.%import_ref.3
+// CHECK:STDOUT:     .InInterfaceArgs = imports.%import_ref.4
+// CHECK:STDOUT:     .G = %G.decl
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %default.import = import <invalid>
+// CHECK:STDOUT:   %G.decl: %G.type = fn_decl @G [template = constants.%G] {
+// CHECK:STDOUT:     %x.patt: %X = binding_pattern x
+// CHECK:STDOUT:     %x.param_patt: %X = value_param_pattern %x.patt, runtime_param0
+// CHECK:STDOUT:   } {
+// CHECK:STDOUT:     %X.ref: type = name_ref X, imports.%import_ref.3 [template = constants.%X]
+// CHECK:STDOUT:     %x.param: %X = value_param runtime_param0
+// CHECK:STDOUT:     %x: %X = bind_name x, %x.param
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic interface @I(constants.%T: type) {
+// CHECK:STDOUT:   %T: type = bind_symbolic_name T, 0 [symbolic = %T (constants.%T)]
+// CHECK:STDOUT:   %T.patt: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt (constants.%T.patt)]
+// CHECK:STDOUT:
+// CHECK:STDOUT: !definition:
+// CHECK:STDOUT:   %I.type: type = facet_type <@I, @I(%T)> [symbolic = %I.type (constants.%I.type.2)]
+// CHECK:STDOUT:   %Self: %I.type.2 = bind_symbolic_name Self, 1 [symbolic = %Self (constants.%Self.2)]
+// CHECK:STDOUT:   %F.type: type = fn_type @F.1, @I(%T) [symbolic = %F.type (constants.%F.type.1)]
+// CHECK:STDOUT:   %F: @I.%F.type (%F.type.1) = struct_value () [symbolic = %F (constants.%F.1)]
+// CHECK:STDOUT:   %.1: type = assoc_entity_type @I.%I.type (%I.type.2), @I.%F.type (%F.type.1) [symbolic = %.1 (constants.%.4)]
+// CHECK:STDOUT:   %.2: @I.%.1 (%.4) = assoc_entity element0, imports.%import_ref.10 [symbolic = %.2 (constants.%.5)]
+// CHECK:STDOUT:
+// CHECK:STDOUT:   interface {
+// CHECK:STDOUT:   !members:
+// CHECK:STDOUT:     .Self = imports.%import_ref.7
+// CHECK:STDOUT:     .F = imports.%import_ref.8
+// CHECK:STDOUT:     witness = (imports.%import_ref.9)
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl: imports.%import_ref.14 as imports.%import_ref.15 {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   witness = imports.%import_ref.16
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @X {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = imports.%import_ref.6
+// CHECK:STDOUT:   complete_type_witness = imports.%import_ref.5
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @InInterfaceArgs {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = imports.%import_ref.12
+// CHECK:STDOUT:   complete_type_witness = imports.%import_ref.11
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @G(%x.param_patt: %X) {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %x.ref: %X = name_ref x, %x
+// CHECK:STDOUT:   %I.ref: %I.type.1 = name_ref I, imports.%import_ref.1 [template = constants.%I]
+// CHECK:STDOUT:   %InInterfaceArgs.ref: type = name_ref InInterfaceArgs, imports.%import_ref.4 [template = constants.%InInterfaceArgs]
+// CHECK:STDOUT:   %I.type: type = facet_type <@I, @I(constants.%InInterfaceArgs)> [template = constants.%I.type.3]
+// CHECK:STDOUT:   %.loc6_35: %.6 = specific_constant imports.%import_ref.8, @I(constants.%InInterfaceArgs) [template = constants.%.7]
+// CHECK:STDOUT:   %F.ref: %.6 = name_ref F, %.loc6_35 [template = constants.%.7]
+// CHECK:STDOUT:   %.loc6_15: %F.type.2 = interface_witness_access constants.%.9, element0 [template = constants.%F.3]
+// CHECK:STDOUT:   %F.call: init %empty_tuple.type = call %.loc6_15()
+// CHECK:STDOUT:   return
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic fn @F.1(constants.%T: type, constants.%Self.1: @I.%I.type (%I.type.2)) {
+// CHECK:STDOUT:
+// CHECK:STDOUT:   fn();
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @F.2();
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @I(constants.%T) {
+// CHECK:STDOUT:   %T => constants.%T
+// CHECK:STDOUT:   %T.patt => constants.%T
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @I(%T) {
+// CHECK:STDOUT:   %T => constants.%T
+// CHECK:STDOUT:   %T.patt => constants.%T
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @F.1(constants.%T, constants.%Self.1) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @I(constants.%InInterfaceArgs) {
+// CHECK:STDOUT:   %T => constants.%InInterfaceArgs
+// CHECK:STDOUT:   %T.patt => constants.%InInterfaceArgs
+// CHECK:STDOUT:
+// CHECK:STDOUT: !definition:
+// CHECK:STDOUT:   %I.type => constants.%I.type.3
+// CHECK:STDOUT:   %Self => constants.%Self.2
+// CHECK:STDOUT:   %F.type => constants.%F.type.2
+// CHECK:STDOUT:   %F => constants.%F.2
+// CHECK:STDOUT:   %.1 => constants.%.6
+// CHECK:STDOUT:   %.2 => constants.%.7
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- impl_in_class_args.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %InClassArgs: type = class_type @InClassArgs [template]
+// CHECK:STDOUT:   %.1: type = struct_type {} [template]
+// CHECK:STDOUT:   %.2: <witness> = complete_type_witness %.1 [template]
+// CHECK:STDOUT:   %C.type: type = generic_class_type @C [template]
+// CHECK:STDOUT:   %C.1: %C.type = struct_value () [template]
+// CHECK:STDOUT:   %T: type = bind_symbolic_name T, 0 [symbolic]
+// CHECK:STDOUT:   %T.patt: type = symbolic_binding_pattern T, 0 [symbolic]
+// CHECK:STDOUT:   %C.3: type = class_type @C, @C(%InClassArgs) [template]
+// CHECK:STDOUT:   %I.type.1: type = generic_interface_type @I [template]
+// CHECK:STDOUT:   %I: %I.type.1 = struct_value () [template]
+// CHECK:STDOUT:   %I.type.2: type = facet_type <@I, @I(%T)> [symbolic]
+// CHECK:STDOUT:   %Self.1: @I.%I.type (%I.type.2) = bind_symbolic_name Self, 1 [symbolic]
+// CHECK:STDOUT:   %Self.2: %I.type.2 = bind_symbolic_name Self, 1 [symbolic]
+// CHECK:STDOUT:   %F.type.1: type = fn_type @F.1, @I(%T) [symbolic]
+// CHECK:STDOUT:   %F.1: %F.type.1 = struct_value () [symbolic]
+// CHECK:STDOUT:   %.3: type = assoc_entity_type %I.type.2, %F.type.1 [symbolic]
+// CHECK:STDOUT:   %.4: %.3 = assoc_entity element0, imports.%import_ref.9 [symbolic]
+// CHECK:STDOUT:   %X: type = class_type @X [template]
+// CHECK:STDOUT:   %I.type.3: type = facet_type <@I, @I(%X)> [template]
+// CHECK:STDOUT:   %F.type.2: type = fn_type @F.2 [template]
+// CHECK:STDOUT:   %F.2: %F.type.2 = struct_value () [template]
+// CHECK:STDOUT:   %F.type.3: type = fn_type @F.1, @I(%X) [template]
+// CHECK:STDOUT:   %F.3: %F.type.3 = struct_value () [template]
+// CHECK:STDOUT:   %.5: type = assoc_entity_type %I.type.3, %F.type.3 [template]
+// CHECK:STDOUT:   %.6: %.5 = assoc_entity element0, imports.%import_ref.9 [template]
+// CHECK:STDOUT:   %.7: %I.type.2 = facet_value %C.3, %C.3 [symbolic]
+// CHECK:STDOUT:   %.8: <witness> = interface_witness (%F.2) [template]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: imports {
+// CHECK:STDOUT:   %import_ref.1: %I.type.1 = import_ref Main//types, inst+7, loaded [template = constants.%I]
+// CHECK:STDOUT:   %import_ref.2: %C.type = import_ref Main//types, inst+32, loaded [template = constants.%C.1]
+// CHECK:STDOUT:   %import_ref.3: type = import_ref Main//types, inst+41, loaded [template = constants.%X]
+// CHECK:STDOUT:   %import_ref.4: <witness> = import_ref Main//types, inst+39, loaded [template = constants.%.2]
+// CHECK:STDOUT:   %import_ref.5 = import_ref Main//types, inst+37, unloaded
+// CHECK:STDOUT:   %import_ref.6 = import_ref Main//types, inst+14, unloaded
+// CHECK:STDOUT:   %import_ref.7 = import_ref Main//types, inst+20, unloaded
+// CHECK:STDOUT:   %import_ref.8: @I.%F.type (%F.type.1) = import_ref Main//types, inst+16, loaded [symbolic = @I.%F (constants.%F.1)]
+// CHECK:STDOUT:   %import_ref.9 = import_ref Main//types, inst+16, unloaded
+// CHECK:STDOUT:   %import_ref.10: <witness> = import_ref Main//types, inst+43, loaded [template = constants.%.2]
+// CHECK:STDOUT:   %import_ref.11 = import_ref Main//types, inst+42, unloaded
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [template] {
+// CHECK:STDOUT:     .I = imports.%import_ref.1
+// CHECK:STDOUT:     .C = imports.%import_ref.2
+// CHECK:STDOUT:     .X = imports.%import_ref.3
+// CHECK:STDOUT:     .InClassArgs = %InClassArgs.decl
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %default.import = import <invalid>
+// CHECK:STDOUT:   %InClassArgs.decl: type = class_decl @InClassArgs [template = constants.%InClassArgs] {} {}
+// CHECK:STDOUT:   impl_decl @impl [template] {} {
+// CHECK:STDOUT:     %C.ref: %C.type = name_ref C, imports.%import_ref.2 [template = constants.%C.1]
+// CHECK:STDOUT:     %InClassArgs.ref: type = name_ref InClassArgs, file.%InClassArgs.decl [template = constants.%InClassArgs]
+// CHECK:STDOUT:     %C: type = class_type @C, @C(constants.%InClassArgs) [template = constants.%C.3]
+// CHECK:STDOUT:     %I.ref: %I.type.1 = name_ref I, imports.%import_ref.1 [template = constants.%I]
+// CHECK:STDOUT:     %X.ref: type = name_ref X, imports.%import_ref.3 [template = constants.%X]
+// CHECK:STDOUT:     %I.type: type = facet_type <@I, @I(constants.%X)> [template = constants.%I.type.3]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic interface @I(constants.%T: type) {
+// CHECK:STDOUT:   %T: type = bind_symbolic_name T, 0 [symbolic = %T (constants.%T)]
+// CHECK:STDOUT:   %T.patt: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt (constants.%T.patt)]
+// CHECK:STDOUT:
+// CHECK:STDOUT: !definition:
+// CHECK:STDOUT:   %I.type: type = facet_type <@I, @I(%T)> [symbolic = %I.type (constants.%I.type.2)]
+// CHECK:STDOUT:   %Self: %I.type.2 = bind_symbolic_name Self, 1 [symbolic = %Self (constants.%Self.2)]
+// CHECK:STDOUT:   %F.type: type = fn_type @F.1, @I(%T) [symbolic = %F.type (constants.%F.type.1)]
+// CHECK:STDOUT:   %F: @I.%F.type (%F.type.1) = struct_value () [symbolic = %F (constants.%F.1)]
+// CHECK:STDOUT:   %.1: type = assoc_entity_type @I.%I.type (%I.type.2), @I.%F.type (%F.type.1) [symbolic = %.1 (constants.%.3)]
+// CHECK:STDOUT:   %.2: @I.%.1 (%.3) = assoc_entity element0, imports.%import_ref.9 [symbolic = %.2 (constants.%.4)]
+// CHECK:STDOUT:
+// CHECK:STDOUT:   interface {
+// CHECK:STDOUT:   !members:
+// CHECK:STDOUT:     .Self = imports.%import_ref.6
+// CHECK:STDOUT:     .F = imports.%import_ref.7
+// CHECK:STDOUT:     witness = (imports.%import_ref.8)
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl: %C as %I.type {
+// CHECK:STDOUT:   %F.decl: %F.type.2 = fn_decl @F.2 [template = constants.%F.2] {} {}
+// CHECK:STDOUT:   %.loc7: <witness> = interface_witness (%F.decl) [template = constants.%.8]
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .F = %F.decl
+// CHECK:STDOUT:   witness = %.loc7
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @InClassArgs {
+// CHECK:STDOUT:   %.loc5: <witness> = complete_type_witness %.1 [template = constants.%.2]
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%InClassArgs
+// CHECK:STDOUT:   complete_type_witness = %.loc5
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic class @C(constants.%T: type) {
+// CHECK:STDOUT:   %T: type = bind_symbolic_name T, 0 [symbolic = %T (constants.%T)]
+// CHECK:STDOUT:   %T.patt: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt (constants.%T.patt)]
+// CHECK:STDOUT:
+// CHECK:STDOUT: !definition:
+// CHECK:STDOUT:
+// CHECK:STDOUT:   class {
+// CHECK:STDOUT:   !members:
+// CHECK:STDOUT:     .Self = imports.%import_ref.5
+// CHECK:STDOUT:     complete_type_witness = imports.%import_ref.4
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @X {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = imports.%import_ref.11
+// CHECK:STDOUT:   complete_type_witness = imports.%import_ref.10
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic fn @F.1(constants.%T: type, constants.%Self.1: @I.%I.type (%I.type.2)) {
+// CHECK:STDOUT:
+// CHECK:STDOUT:   fn();
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @F.2() {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   return
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @C(constants.%T) {
+// CHECK:STDOUT:   %T => constants.%T
+// CHECK:STDOUT:   %T.patt => constants.%T
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @C(constants.%InClassArgs) {
+// CHECK:STDOUT:   %T => constants.%InClassArgs
+// CHECK:STDOUT:   %T.patt => constants.%InClassArgs
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @I(constants.%T) {
+// CHECK:STDOUT:   %T => constants.%T
+// CHECK:STDOUT:   %T.patt => constants.%T
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @I(%T) {
+// CHECK:STDOUT:   %T => constants.%T
+// CHECK:STDOUT:   %T.patt => constants.%T
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @F.1(constants.%T, constants.%Self.1) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @I(constants.%X) {
+// CHECK:STDOUT:   %T => constants.%X
+// CHECK:STDOUT:   %T.patt => constants.%X
+// CHECK:STDOUT:
+// CHECK:STDOUT: !definition:
+// CHECK:STDOUT:   %I.type => constants.%I.type.3
+// CHECK:STDOUT:   %Self => constants.%Self.2
+// CHECK:STDOUT:   %F.type => constants.%F.type.3
+// CHECK:STDOUT:   %F => constants.%F.3
+// CHECK:STDOUT:   %.1 => constants.%.5
+// CHECK:STDOUT:   %.2 => constants.%.6
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @F.1(constants.%X, constants.%.7) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- use_impl_in_class_args.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %C.type: type = generic_class_type @C [template]
+// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [template]
+// CHECK:STDOUT:   %C.1: %C.type = struct_value () [template]
+// CHECK:STDOUT:   %.1: type = struct_type {} [template]
+// CHECK:STDOUT:   %.2: <witness> = complete_type_witness %.1 [template]
+// CHECK:STDOUT:   %T: type = bind_symbolic_name T, 0 [symbolic]
+// CHECK:STDOUT:   %T.patt: type = symbolic_binding_pattern T, 0 [symbolic]
+// CHECK:STDOUT:   %InClassArgs: type = class_type @InClassArgs [template]
+// CHECK:STDOUT:   %C.3: type = class_type @C, @C(%InClassArgs) [template]
+// CHECK:STDOUT:   %H.type: type = fn_type @H [template]
+// CHECK:STDOUT:   %H: %H.type = struct_value () [template]
+// CHECK:STDOUT:   %I.type.1: type = generic_interface_type @I [template]
+// CHECK:STDOUT:   %I: %I.type.1 = struct_value () [template]
+// CHECK:STDOUT:   %I.type.2: type = facet_type <@I, @I(%T)> [symbolic]
+// CHECK:STDOUT:   %Self.1: @I.%I.type (%I.type.2) = bind_symbolic_name Self, 1 [symbolic]
+// CHECK:STDOUT:   %Self.2: %I.type.2 = bind_symbolic_name Self, 1 [symbolic]
+// CHECK:STDOUT:   %F.type.1: type = fn_type @F.1, @I(%T) [symbolic]
+// CHECK:STDOUT:   %F.1: %F.type.1 = struct_value () [symbolic]
+// CHECK:STDOUT:   %.4: type = assoc_entity_type %I.type.2, %F.type.1 [symbolic]
+// CHECK:STDOUT:   %.5: %.4 = assoc_entity element0, imports.%import_ref.12 [symbolic]
+// CHECK:STDOUT:   %X: type = class_type @X [template]
+// CHECK:STDOUT:   %I.type.3: type = facet_type <@I, @I(%X)> [template]
+// CHECK:STDOUT:   %F.type.2: type = fn_type @F.1, @I(%X) [template]
+// CHECK:STDOUT:   %F.2: %F.type.2 = struct_value () [template]
+// CHECK:STDOUT:   %.6: type = assoc_entity_type %I.type.3, %F.type.2 [template]
+// CHECK:STDOUT:   %.7: %.6 = assoc_entity element0, imports.%import_ref.12 [template]
+// CHECK:STDOUT:   %.8: %.4 = assoc_entity element0, imports.%import_ref.15 [symbolic]
+// CHECK:STDOUT:   %F.type.3: type = fn_type @F.2 [template]
+// CHECK:STDOUT:   %F.3: %F.type.3 = struct_value () [template]
+// CHECK:STDOUT:   %.9: <witness> = interface_witness (%F.3) [template]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: imports {
+// CHECK:STDOUT:   %import_ref.1: %I.type.1 = import_ref Main//types, inst+7, loaded [template = constants.%I]
+// CHECK:STDOUT:   %import_ref.2: %C.type = import_ref Main//types, inst+32, loaded [template = constants.%C.1]
+// CHECK:STDOUT:   %import_ref.3: type = import_ref Main//types, inst+41, loaded [template = constants.%X]
+// CHECK:STDOUT:   %import_ref.4: type = import_ref Main//impl_in_class_args, inst+5, loaded [template = constants.%InClassArgs]
+// CHECK:STDOUT:   %import_ref.5: <witness> = import_ref Main//types, inst+39, loaded [template = constants.%.2]
+// CHECK:STDOUT:   %import_ref.6 = import_ref Main//types, inst+37, unloaded
+// CHECK:STDOUT:   %import_ref.7: <witness> = import_ref Main//impl_in_class_args, inst+8, loaded [template = constants.%.2]
+// CHECK:STDOUT:   %import_ref.8 = import_ref Main//impl_in_class_args, inst+6, unloaded
+// CHECK:STDOUT:   %import_ref.9 = import_ref Main//types, inst+14, unloaded
+// CHECK:STDOUT:   %import_ref.10: @I.%.1 (%.4) = import_ref Main//types, inst+20, loaded [symbolic = @I.%.2 (constants.%.8)]
+// CHECK:STDOUT:   %import_ref.11 = import_ref Main//types, inst+16, unloaded
+// CHECK:STDOUT:   %import_ref.12 = import_ref Main//types, inst+16, unloaded
+// CHECK:STDOUT:   %import_ref.13: <witness> = import_ref Main//types, inst+43, loaded [template = constants.%.2]
+// CHECK:STDOUT:   %import_ref.14 = import_ref Main//types, inst+42, unloaded
+// CHECK:STDOUT:   %import_ref.16: type = import_ref Main//impl_in_class_args, inst+25, loaded [template = constants.%C.3]
+// CHECK:STDOUT:   %import_ref.17: type = import_ref Main//impl_in_class_args, inst+58, loaded [template = constants.%I.type.3]
+// CHECK:STDOUT:   %import_ref.18: <witness> = import_ref Main//impl_in_class_args, inst+69, loaded [template = constants.%.9]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [template] {
+// CHECK:STDOUT:     .I = imports.%import_ref.1
+// CHECK:STDOUT:     .C = imports.%import_ref.2
+// CHECK:STDOUT:     .X = imports.%import_ref.3
+// CHECK:STDOUT:     .InClassArgs = imports.%import_ref.4
+// CHECK:STDOUT:     .H = %H.decl
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %default.import = import <invalid>
+// CHECK:STDOUT:   %H.decl: %H.type = fn_decl @H [template = constants.%H] {
+// CHECK:STDOUT:     %c.patt: %C.3 = binding_pattern c
+// CHECK:STDOUT:     %c.param_patt: %C.3 = value_param_pattern %c.patt, runtime_param0
+// CHECK:STDOUT:   } {
+// CHECK:STDOUT:     %C.ref: %C.type = name_ref C, imports.%import_ref.2 [template = constants.%C.1]
+// CHECK:STDOUT:     %InClassArgs.ref: type = name_ref InClassArgs, imports.%import_ref.4 [template = constants.%InClassArgs]
+// CHECK:STDOUT:     %C: type = class_type @C, @C(constants.%InClassArgs) [template = constants.%C.3]
+// CHECK:STDOUT:     %c.param: %C.3 = value_param runtime_param0
+// CHECK:STDOUT:     %c: %C.3 = bind_name c, %c.param
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic interface @I(constants.%T: type) {
+// CHECK:STDOUT:   %T: type = bind_symbolic_name T, 0 [symbolic = %T (constants.%T)]
+// CHECK:STDOUT:   %T.patt: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt (constants.%T.patt)]
+// CHECK:STDOUT:
+// CHECK:STDOUT: !definition:
+// CHECK:STDOUT:   %I.type: type = facet_type <@I, @I(%T)> [symbolic = %I.type (constants.%I.type.2)]
+// CHECK:STDOUT:   %Self: %I.type.2 = bind_symbolic_name Self, 1 [symbolic = %Self (constants.%Self.2)]
+// CHECK:STDOUT:   %F.type: type = fn_type @F.1, @I(%T) [symbolic = %F.type (constants.%F.type.1)]
+// CHECK:STDOUT:   %F: @I.%F.type (%F.type.1) = struct_value () [symbolic = %F (constants.%F.1)]
+// CHECK:STDOUT:   %.1: type = assoc_entity_type @I.%I.type (%I.type.2), @I.%F.type (%F.type.1) [symbolic = %.1 (constants.%.4)]
+// CHECK:STDOUT:   %.2: @I.%.1 (%.4) = assoc_entity element0, imports.%import_ref.12 [symbolic = %.2 (constants.%.5)]
+// CHECK:STDOUT:
+// CHECK:STDOUT:   interface {
+// CHECK:STDOUT:   !members:
+// CHECK:STDOUT:     .Self = imports.%import_ref.9
+// CHECK:STDOUT:     .F = imports.%import_ref.10
+// CHECK:STDOUT:     witness = (imports.%import_ref.11)
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl: imports.%import_ref.16 as imports.%import_ref.17 {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   witness = imports.%import_ref.18
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic class @C(constants.%T: type) {
+// CHECK:STDOUT:   %T: type = bind_symbolic_name T, 0 [symbolic = %T (constants.%T)]
+// CHECK:STDOUT:   %T.patt: type = symbolic_binding_pattern T, 0 [symbolic = %T.patt (constants.%T.patt)]
+// CHECK:STDOUT:
+// CHECK:STDOUT: !definition:
+// CHECK:STDOUT:
+// CHECK:STDOUT:   class {
+// CHECK:STDOUT:   !members:
+// CHECK:STDOUT:     .Self = imports.%import_ref.6
+// CHECK:STDOUT:     complete_type_witness = imports.%import_ref.5
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @InClassArgs {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = imports.%import_ref.8
+// CHECK:STDOUT:   complete_type_witness = imports.%import_ref.7
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @X {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = imports.%import_ref.14
+// CHECK:STDOUT:   complete_type_witness = imports.%import_ref.13
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @H(%c.param_patt: %C.3) {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %c.ref: %C.3 = name_ref c, %c
+// CHECK:STDOUT:   %I.ref: %I.type.1 = name_ref I, imports.%import_ref.1 [template = constants.%I]
+// CHECK:STDOUT:   %X.ref: type = name_ref X, imports.%import_ref.3 [template = constants.%X]
+// CHECK:STDOUT:   %I.type: type = facet_type <@I, @I(constants.%X)> [template = constants.%I.type.3]
+// CHECK:STDOUT:   %.loc6_34: %.6 = specific_constant imports.%import_ref.10, @I(constants.%X) [template = constants.%.7]
+// CHECK:STDOUT:   %F.ref: %.6 = name_ref F, %.loc6_34 [template = constants.%.7]
+// CHECK:STDOUT:   %.loc6_28: %F.type.2 = interface_witness_access constants.%.9, element0 [template = constants.%F.3]
+// CHECK:STDOUT:   %F.call: init %empty_tuple.type = call %.loc6_28()
+// CHECK:STDOUT:   return
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic fn @F.1(constants.%T: type, constants.%Self.1: @I.%I.type (%I.type.2)) {
+// CHECK:STDOUT:
+// CHECK:STDOUT:   fn();
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @F.2();
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @C(constants.%T) {
+// CHECK:STDOUT:   %T => constants.%T
+// CHECK:STDOUT:   %T.patt => constants.%T
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @C(constants.%InClassArgs) {
+// CHECK:STDOUT:   %T => constants.%InClassArgs
+// CHECK:STDOUT:   %T.patt => constants.%InClassArgs
+// CHECK:STDOUT:
+// CHECK:STDOUT: !definition:
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @I(constants.%T) {
+// CHECK:STDOUT:   %T => constants.%T
+// CHECK:STDOUT:   %T.patt => constants.%T
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @I(%T) {
+// CHECK:STDOUT:   %T => constants.%T
+// CHECK:STDOUT:   %T.patt => constants.%T
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @F.1(constants.%T, constants.%Self.1) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @I(constants.%X) {
+// CHECK:STDOUT:   %T => constants.%X
+// CHECK:STDOUT:   %T.patt => constants.%X
+// CHECK:STDOUT:
+// CHECK:STDOUT: !definition:
+// CHECK:STDOUT:   %I.type => constants.%I.type.3
+// CHECK:STDOUT:   %Self => constants.%Self.2
+// CHECK:STDOUT:   %F.type => constants.%F.type.2
+// CHECK:STDOUT:   %F => constants.%F.2
+// CHECK:STDOUT:   %.1 => constants.%.6
+// CHECK:STDOUT:   %.2 => constants.%.7
+// CHECK:STDOUT: }
+// CHECK:STDOUT: