Properly set the name for C++ overload set instructions in SemIR (#6156)

This is a followup of #5891. Part of #5915.
2026-10-05 22:02:55 +01:00 · 2025-10-06 07:36:28 +00:00
parent b99bc00632
commit 5f561282eb
37 changed files with 1128 additions and 1096 deletions
@@ -492,14 +492,14 @@ fn F() {
 // CHECK:STDOUT:   %S: type = class_type @S [concrete]
 // CHECK:STDOUT:   %ptr.5c7: type = ptr_type %S [concrete]
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
-// CHECK:STDOUT:   %.177: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.dcb: %.177 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %S.foo.cpp_overload_set.type: type = cpp_overload_set_type @S.foo.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %S.foo.cpp_overload_set.value: %S.foo.cpp_overload_set.type = cpp_overload_set_value @S.foo.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %S.foo.type: type = fn_type @S.foo [concrete]
 // CHECK:STDOUT:   %S.foo: %S.foo.type = struct_value () [concrete]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: imports {
-// CHECK:STDOUT:   %.dcb: %.177 = cpp_overload_set_value @<null name> [concrete = constants.%.dcb]
+// CHECK:STDOUT:   %S.foo.cpp_overload_set.value: %S.foo.cpp_overload_set.type = cpp_overload_set_value @S.foo.cpp_overload_set [concrete = constants.%S.foo.cpp_overload_set.value]
 // CHECK:STDOUT:   %S.foo.decl: %S.foo.type = fn_decl @S.foo [concrete = constants.%S.foo] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
@@ -511,7 +511,7 @@ fn F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %s.ref: %ptr.5c7 = name_ref s, %s
 // CHECK:STDOUT:   %.loc8: ref %S = deref %s.ref
-// CHECK:STDOUT:   %foo.ref: %.177 = name_ref foo, imports.%.dcb [concrete = constants.%.dcb]
+// CHECK:STDOUT:   %foo.ref: %S.foo.cpp_overload_set.type = name_ref foo, imports.%S.foo.cpp_overload_set.value [concrete = constants.%S.foo.cpp_overload_set.value]
 // CHECK:STDOUT:   %bound_method: <bound method> = bound_method %.loc8, %foo.ref
 // CHECK:STDOUT:   %addr: %ptr.5c7 = addr_of %.loc8
 // CHECK:STDOUT:   %S.foo.call: init %empty_tuple.type = call imports.%S.foo.decl(%addr)
@@ -523,13 +523,13 @@ fn F() {
 // CHECK:STDOUT: constants {
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
 // CHECK:STDOUT:   %C: type = class_type @C [concrete]
-// CHECK:STDOUT:   %.d40: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.40b: %.d40 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.type: type = cpp_overload_set_type @C.C.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.value: %C.C.cpp_overload_set.type = cpp_overload_set_value @C.C.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %ptr.d9e: type = ptr_type %C [concrete]
 // CHECK:STDOUT:   %C__carbon_thunk.type: type = fn_type @C__carbon_thunk [concrete]
 // CHECK:STDOUT:   %C__carbon_thunk: %C__carbon_thunk.type = struct_value () [concrete]
-// CHECK:STDOUT:   %.cd1: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.e4a: %.cd1 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %C.foo.cpp_overload_set.type: type = cpp_overload_set_type @C.foo.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %C.foo.cpp_overload_set.value: %C.foo.cpp_overload_set.type = cpp_overload_set_value @C.foo.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %C.foo.type: type = fn_type @C.foo [concrete]
 // CHECK:STDOUT:   %C.foo: %C.foo.type = struct_value () [concrete]
 // CHECK:STDOUT:   %type_where: type = facet_type <type where .Self impls <CanDestroy>> [concrete]
@@ -544,13 +544,13 @@ fn F() {
 // CHECK:STDOUT:     import Cpp//...
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %C.decl: type = class_decl @C [concrete = constants.%C] {} {}
-// CHECK:STDOUT:   %.40b: %.d40 = cpp_overload_set_value @<null name> [concrete = constants.%.40b]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.value: %C.C.cpp_overload_set.type = cpp_overload_set_value @C.C.cpp_overload_set [concrete = constants.%C.C.cpp_overload_set.value]
 // CHECK:STDOUT:   %C__carbon_thunk.decl: %C__carbon_thunk.type = fn_decl @C__carbon_thunk [concrete = constants.%C__carbon_thunk] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %.e4a: %.cd1 = cpp_overload_set_value @<null name> [concrete = constants.%.e4a]
+// CHECK:STDOUT:   %C.foo.cpp_overload_set.value: %C.foo.cpp_overload_set.type = cpp_overload_set_value @C.foo.cpp_overload_set [concrete = constants.%C.foo.cpp_overload_set.value]
 // CHECK:STDOUT:   %C.foo.decl: %C.foo.type = fn_decl @C.foo [concrete = constants.%C.foo] {} {}
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -558,7 +558,7 @@ fn F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref.loc8: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %C.ref.loc8_6: type = name_ref C, imports.%C.decl [concrete = constants.%C]
-// CHECK:STDOUT:   %C.ref.loc8_8: %.d40 = name_ref C, imports.%.40b [concrete = constants.%.40b]
+// CHECK:STDOUT:   %C.ref.loc8_8: %C.C.cpp_overload_set.type = name_ref C, imports.%C.C.cpp_overload_set.value [concrete = constants.%C.C.cpp_overload_set.value]
 // CHECK:STDOUT:   %.loc8_11.1: ref %C = temporary_storage
 // CHECK:STDOUT:   %addr.loc8_11.1: %ptr.d9e = addr_of %.loc8_11.1
 // CHECK:STDOUT:   %C__carbon_thunk.call: init %empty_tuple.type = call imports.%C__carbon_thunk.decl(%addr.loc8_11.1)
@@ -566,7 +566,7 @@ fn F() {
 // CHECK:STDOUT:   %.loc8_11.3: ref %C = temporary %.loc8_11.1, %.loc8_11.2
 // CHECK:STDOUT:   %Cpp.ref.loc9: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %C.ref.loc9: type = name_ref C, imports.%C.decl [concrete = constants.%C]
-// CHECK:STDOUT:   %foo.ref: %.cd1 = name_ref foo, imports.%.e4a [concrete = constants.%.e4a]
+// CHECK:STDOUT:   %foo.ref: %C.foo.cpp_overload_set.type = name_ref foo, imports.%C.foo.cpp_overload_set.value [concrete = constants.%C.foo.cpp_overload_set.value]
 // CHECK:STDOUT:   %C.foo.call: init %empty_tuple.type = call imports.%C.foo.decl()
 // CHECK:STDOUT:   %facet_value: %type_where = facet_value constants.%C, () [concrete = constants.%facet_value]
 // CHECK:STDOUT:   %.loc8_11.4: %type_where = converted constants.%C, %facet_value [concrete = constants.%facet_value]
@@ -583,8 +583,8 @@ fn F() {
 // CHECK:STDOUT: constants {
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
 // CHECK:STDOUT:   %DerivedPublic: type = class_type @DerivedPublic [concrete]
-// CHECK:STDOUT:   %.5a6: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.607: %.5a6 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %DerivedPublic.foo.cpp_overload_set.type: type = cpp_overload_set_type @DerivedPublic.foo.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %DerivedPublic.foo.cpp_overload_set.value: %DerivedPublic.foo.cpp_overload_set.type = cpp_overload_set_value @DerivedPublic.foo.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %Base.foo.type: type = fn_type @Base.foo [concrete]
 // CHECK:STDOUT:   %Base.foo: %Base.foo.type = struct_value () [concrete]
 // CHECK:STDOUT: }
@@ -595,7 +595,7 @@ fn F() {
 // CHECK:STDOUT:     import Cpp//...
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %DerivedPublic.decl: type = class_decl @DerivedPublic [concrete = constants.%DerivedPublic] {} {}
-// CHECK:STDOUT:   %.607: %.5a6 = cpp_overload_set_value @<null name> [concrete = constants.%.607]
+// CHECK:STDOUT:   %DerivedPublic.foo.cpp_overload_set.value: %DerivedPublic.foo.cpp_overload_set.type = cpp_overload_set_value @DerivedPublic.foo.cpp_overload_set [concrete = constants.%DerivedPublic.foo.cpp_overload_set.value]
 // CHECK:STDOUT:   %Base.foo.decl: %Base.foo.type = fn_decl @Base.foo [concrete = constants.%Base.foo] {} {}
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -603,7 +603,7 @@ fn F() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %DerivedPublic.ref: type = name_ref DerivedPublic, imports.%DerivedPublic.decl [concrete = constants.%DerivedPublic]
-// CHECK:STDOUT:   %foo.ref: %.5a6 = name_ref foo, imports.%.607 [concrete = constants.%.607]
+// CHECK:STDOUT:   %foo.ref: %DerivedPublic.foo.cpp_overload_set.type = name_ref foo, imports.%DerivedPublic.foo.cpp_overload_set.value [concrete = constants.%DerivedPublic.foo.cpp_overload_set.value]
 // CHECK:STDOUT:   %Base.foo.call: init %empty_tuple.type = call imports.%Base.foo.decl()
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
@@ -464,15 +464,15 @@ class V {
 // CHECK:STDOUT: constants {
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
 // CHECK:STDOUT:   %Base: type = class_type @Base [concrete]
-// CHECK:STDOUT:   %.75e: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.750: %.75e = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %Base.base_fn.cpp_overload_set.type: type = cpp_overload_set_type @Base.base_fn.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %Base.base_fn.cpp_overload_set.value: %Base.base_fn.cpp_overload_set.type = cpp_overload_set_value @Base.base_fn.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %Base.base_fn.type: type = fn_type @Base.base_fn [concrete]
 // CHECK:STDOUT:   %Base.base_fn: %Base.base_fn.type = struct_value () [concrete]
 // CHECK:STDOUT:   %Derived: type = class_type @Derived [concrete]
-// CHECK:STDOUT:   %.809: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.22a: %.809 = cpp_overload_set_value @<null name> [concrete]
-// CHECK:STDOUT:   %.5f9: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.24a: %.5f9 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %Derived.base_fn.cpp_overload_set.type: type = cpp_overload_set_type @Derived.base_fn.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %Derived.base_fn.cpp_overload_set.value: %Derived.base_fn.cpp_overload_set.type = cpp_overload_set_value @Derived.base_fn.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %Derived.derived_fn.cpp_overload_set.type: type = cpp_overload_set_type @Derived.derived_fn.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %Derived.derived_fn.cpp_overload_set.value: %Derived.derived_fn.cpp_overload_set.type = cpp_overload_set_value @Derived.derived_fn.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %Derived.derived_fn.type: type = fn_type @Derived.derived_fn [concrete]
 // CHECK:STDOUT:   %Derived.derived_fn: %Derived.derived_fn.type = struct_value () [concrete]
 // CHECK:STDOUT: }
@@ -484,11 +484,11 @@ class V {
 // CHECK:STDOUT:     import Cpp//...
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %Base.decl: type = class_decl @Base [concrete = constants.%Base] {} {}
-// CHECK:STDOUT:   %.750: %.75e = cpp_overload_set_value @<null name> [concrete = constants.%.750]
+// CHECK:STDOUT:   %Base.base_fn.cpp_overload_set.value: %Base.base_fn.cpp_overload_set.type = cpp_overload_set_value @Base.base_fn.cpp_overload_set [concrete = constants.%Base.base_fn.cpp_overload_set.value]
 // CHECK:STDOUT:   %Base.base_fn.decl: %Base.base_fn.type = fn_decl @Base.base_fn [concrete = constants.%Base.base_fn] {} {}
 // CHECK:STDOUT:   %Derived.decl: type = class_decl @Derived [concrete = constants.%Derived] {} {}
-// CHECK:STDOUT:   %.22a: %.809 = cpp_overload_set_value @<null name> [concrete = constants.%.22a]
-// CHECK:STDOUT:   %.24a: %.5f9 = cpp_overload_set_value @<null name> [concrete = constants.%.24a]
+// CHECK:STDOUT:   %Derived.base_fn.cpp_overload_set.value: %Derived.base_fn.cpp_overload_set.type = cpp_overload_set_value @Derived.base_fn.cpp_overload_set [concrete = constants.%Derived.base_fn.cpp_overload_set.value]
+// CHECK:STDOUT:   %Derived.derived_fn.cpp_overload_set.value: %Derived.derived_fn.cpp_overload_set.type = cpp_overload_set_value @Derived.derived_fn.cpp_overload_set [concrete = constants.%Derived.derived_fn.cpp_overload_set.value]
 // CHECK:STDOUT:   %Derived.derived_fn.decl: %Derived.derived_fn.type = fn_decl @Derived.derived_fn [concrete = constants.%Derived.derived_fn] {} {}
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -496,15 +496,15 @@ class V {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref.loc8: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %Base.ref: type = name_ref Base, imports.%Base.decl [concrete = constants.%Base]
-// CHECK:STDOUT:   %base_fn.ref.loc8: %.75e = name_ref base_fn, imports.%.750 [concrete = constants.%.750]
+// CHECK:STDOUT:   %base_fn.ref.loc8: %Base.base_fn.cpp_overload_set.type = name_ref base_fn, imports.%Base.base_fn.cpp_overload_set.value [concrete = constants.%Base.base_fn.cpp_overload_set.value]
 // CHECK:STDOUT:   %Base.base_fn.call.loc8: init %empty_tuple.type = call imports.%Base.base_fn.decl()
 // CHECK:STDOUT:   %Cpp.ref.loc9: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %Derived.ref.loc9: type = name_ref Derived, imports.%Derived.decl [concrete = constants.%Derived]
-// CHECK:STDOUT:   %base_fn.ref.loc9: %.809 = name_ref base_fn, imports.%.22a [concrete = constants.%.22a]
+// CHECK:STDOUT:   %base_fn.ref.loc9: %Derived.base_fn.cpp_overload_set.type = name_ref base_fn, imports.%Derived.base_fn.cpp_overload_set.value [concrete = constants.%Derived.base_fn.cpp_overload_set.value]
 // CHECK:STDOUT:   %Base.base_fn.call.loc9: init %empty_tuple.type = call imports.%Base.base_fn.decl()
 // CHECK:STDOUT:   %Cpp.ref.loc10: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %Derived.ref.loc10: type = name_ref Derived, imports.%Derived.decl [concrete = constants.%Derived]
-// CHECK:STDOUT:   %derived_fn.ref: %.5f9 = name_ref derived_fn, imports.%.24a [concrete = constants.%.24a]
+// CHECK:STDOUT:   %derived_fn.ref: %Derived.derived_fn.cpp_overload_set.type = name_ref derived_fn, imports.%Derived.derived_fn.cpp_overload_set.value [concrete = constants.%Derived.derived_fn.cpp_overload_set.value]
 // CHECK:STDOUT:   %Derived.derived_fn.call: init %empty_tuple.type = call imports.%Derived.derived_fn.decl()
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
@@ -582,15 +582,15 @@ class V {
 // CHECK:STDOUT:   %Derived: type = class_type @Derived [concrete]
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
 // CHECK:STDOUT:   %Base: type = class_type @Base [concrete]
-// CHECK:STDOUT:   %.5b0: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.e54: %.5b0 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %Derived.f.cpp_overload_set.type: type = cpp_overload_set_type @Derived.f.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %Derived.f.cpp_overload_set.value: %Derived.f.cpp_overload_set.type = cpp_overload_set_value @Derived.f.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %const: type = const_type %Base [concrete]
 // CHECK:STDOUT:   %ptr.a97: type = ptr_type %const [concrete]
 // CHECK:STDOUT:   %f__carbon_thunk.type: type = fn_type @f__carbon_thunk [concrete]
 // CHECK:STDOUT:   %f__carbon_thunk: %f__carbon_thunk.type = struct_value () [concrete]
 // CHECK:STDOUT:   %ptr.fb2: type = ptr_type %Base [concrete]
-// CHECK:STDOUT:   %.7c6: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.362: %.7c6 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %Base.g.cpp_overload_set.type: type = cpp_overload_set_type @Base.g.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %Base.g.cpp_overload_set.value: %Base.g.cpp_overload_set.type = cpp_overload_set_value @Base.g.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %g__carbon_thunk.type: type = fn_type @g__carbon_thunk [concrete]
 // CHECK:STDOUT:   %g__carbon_thunk: %g__carbon_thunk.type = struct_value () [concrete]
 // CHECK:STDOUT: }
@@ -603,13 +603,13 @@ class V {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %Derived.decl: type = class_decl @Derived [concrete = constants.%Derived] {} {}
 // CHECK:STDOUT:   %Base.decl: type = class_decl @Base [concrete = constants.%Base] {} {}
-// CHECK:STDOUT:   %.e54: %.5b0 = cpp_overload_set_value @<null name> [concrete = constants.%.e54]
+// CHECK:STDOUT:   %Derived.f.cpp_overload_set.value: %Derived.f.cpp_overload_set.type = cpp_overload_set_value @Derived.f.cpp_overload_set [concrete = constants.%Derived.f.cpp_overload_set.value]
 // CHECK:STDOUT:   %f__carbon_thunk.decl: %f__carbon_thunk.type = fn_decl @f__carbon_thunk [concrete = constants.%f__carbon_thunk] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %.362: %.7c6 = cpp_overload_set_value @<null name> [concrete = constants.%.362]
+// CHECK:STDOUT:   %Base.g.cpp_overload_set.value: %Base.g.cpp_overload_set.type = cpp_overload_set_value @Base.g.cpp_overload_set [concrete = constants.%Base.g.cpp_overload_set.value]
 // CHECK:STDOUT:   %g__carbon_thunk.decl: %g__carbon_thunk.type = fn_decl @g__carbon_thunk [concrete = constants.%g__carbon_thunk] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
@@ -620,7 +620,7 @@ class V {
 // CHECK:STDOUT: fn @CallDirect(%d.param: %Derived) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %d.ref: %Derived = name_ref d, %d
-// CHECK:STDOUT:   %f.ref: %.5b0 = name_ref f, imports.%.e54 [concrete = constants.%.e54]
+// CHECK:STDOUT:   %f.ref: %Derived.f.cpp_overload_set.type = name_ref f, imports.%Derived.f.cpp_overload_set.value [concrete = constants.%Derived.f.cpp_overload_set.value]
 // CHECK:STDOUT:   %bound_method: <bound method> = bound_method %d.ref, %f.ref
 // CHECK:STDOUT:   %.loc8_3.1: ref %Base = class_element_access %d.ref, element0
 // CHECK:STDOUT:   %.loc8_3.2: ref %Base = converted %d.ref, %.loc8_3.1
@@ -638,7 +638,7 @@ class V {
 // CHECK:STDOUT:   %d.ref: %Derived = name_ref d, %d
 // CHECK:STDOUT:   %Cpp.ref.loc14: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %Base.ref: type = name_ref Base, imports.%Base.decl [concrete = constants.%Base]
-// CHECK:STDOUT:   %g.ref: %.7c6 = name_ref g, imports.%.362 [concrete = constants.%.362]
+// CHECK:STDOUT:   %g.ref: %Base.g.cpp_overload_set.type = name_ref g, imports.%Base.g.cpp_overload_set.value [concrete = constants.%Base.g.cpp_overload_set.value]
 // CHECK:STDOUT:   %bound_method: <bound method> = bound_method %d.ref, %g.ref
 // CHECK:STDOUT:   %.loc14_3.1: ref %Base = class_element_access %d.ref, element0
 // CHECK:STDOUT:   %.loc14_3.2: ref %Base = converted %d.ref, %.loc14_3.1
@@ -337,8 +337,8 @@ fn MyF(bar: Cpp.Bar*);
 // CHECK:STDOUT: constants {
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
 // CHECK:STDOUT:   %Bar: type = class_type @Bar [concrete]
-// CHECK:STDOUT:   %.c07: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.617: %.c07 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %Bar.foo.cpp_overload_set.type: type = cpp_overload_set_type @Bar.foo.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %Bar.foo.cpp_overload_set.value: %Bar.foo.cpp_overload_set.type = cpp_overload_set_value @Bar.foo.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %Bar.foo.type: type = fn_type @Bar.foo [concrete]
 // CHECK:STDOUT:   %Bar.foo: %Bar.foo.type = struct_value () [concrete]
 // CHECK:STDOUT: }
@@ -349,7 +349,7 @@ fn MyF(bar: Cpp.Bar*);
 // CHECK:STDOUT:     import Cpp//...
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %Bar.decl: type = class_decl @Bar [concrete = constants.%Bar] {} {}
-// CHECK:STDOUT:   %.617: %.c07 = cpp_overload_set_value @<null name> [concrete = constants.%.617]
+// CHECK:STDOUT:   %Bar.foo.cpp_overload_set.value: %Bar.foo.cpp_overload_set.type = cpp_overload_set_value @Bar.foo.cpp_overload_set [concrete = constants.%Bar.foo.cpp_overload_set.value]
 // CHECK:STDOUT:   %Bar.foo.decl: %Bar.foo.type = fn_decl @Bar.foo [concrete = constants.%Bar.foo] {} {}
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -357,7 +357,7 @@ fn MyF(bar: Cpp.Bar*);
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %Bar.ref: type = name_ref Bar, imports.%Bar.decl [concrete = constants.%Bar]
-// CHECK:STDOUT:   %foo.ref: %.c07 = name_ref foo, imports.%.617 [concrete = constants.%.617]
+// CHECK:STDOUT:   %foo.ref: %Bar.foo.cpp_overload_set.type = name_ref foo, imports.%Bar.foo.cpp_overload_set.value [concrete = constants.%Bar.foo.cpp_overload_set.value]
 // CHECK:STDOUT:   %Bar.foo.call: init %empty_tuple.type = call imports.%Bar.foo.decl()
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
@@ -496,8 +496,8 @@ fn MyF(bar: Cpp.Bar*);
 // CHECK:STDOUT:   %complete_type.fff: <witness> = complete_type_witness %struct_type.base.36d [concrete]
 // CHECK:STDOUT:   %MyF.type: type = fn_type @MyF [concrete]
 // CHECK:STDOUT:   %MyF: %MyF.type = struct_value () [concrete]
-// CHECK:STDOUT:   %.c07: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.617: %.c07 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %Bar.foo.cpp_overload_set.type: type = cpp_overload_set_type @Bar.foo.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %Bar.foo.cpp_overload_set.value: %Bar.foo.cpp_overload_set.type = cpp_overload_set_value @Bar.foo.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %Bar.foo.type: type = fn_type @Bar.foo [concrete]
 // CHECK:STDOUT:   %Bar.foo: %Bar.foo.type = struct_value () [concrete]
 // CHECK:STDOUT: }
@@ -508,7 +508,7 @@ fn MyF(bar: Cpp.Bar*);
 // CHECK:STDOUT:     import Cpp//...
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %Bar.decl: type = class_decl @Bar [concrete = constants.%Bar] {} {}
-// CHECK:STDOUT:   %.617: %.c07 = cpp_overload_set_value @<null name> [concrete = constants.%.617]
+// CHECK:STDOUT:   %Bar.foo.cpp_overload_set.value: %Bar.foo.cpp_overload_set.type = cpp_overload_set_value @Bar.foo.cpp_overload_set [concrete = constants.%Bar.foo.cpp_overload_set.value]
 // CHECK:STDOUT:   %Bar.foo.decl: %Bar.foo.type = fn_decl @Bar.foo [concrete = constants.%Bar.foo] {} {}
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -535,7 +535,7 @@ fn MyF(bar: Cpp.Bar*);
 // CHECK:STDOUT: fn @MyF() {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Derived.ref: type = name_ref Derived, file.%Derived.decl [concrete = constants.%Derived]
-// CHECK:STDOUT:   %foo.ref: %.c07 = name_ref foo, imports.%.617 [concrete = constants.%.617]
+// CHECK:STDOUT:   %foo.ref: %Bar.foo.cpp_overload_set.type = name_ref foo, imports.%Bar.foo.cpp_overload_set.value [concrete = constants.%Bar.foo.cpp_overload_set.value]
 // CHECK:STDOUT:   %Bar.foo.call: init %empty_tuple.type = call imports.%Bar.foo.decl()
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
@@ -275,8 +275,8 @@ fn F() {
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
 // CHECK:STDOUT:   %C: type = class_type @C [concrete]
 // CHECK:STDOUT:   %pattern_type.217: type = pattern_type %C [concrete]
-// CHECK:STDOUT:   %.d40: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.40b: %.d40 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.type: type = cpp_overload_set_type @C.C.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.value: %C.C.cpp_overload_set.type = cpp_overload_set_value @C.C.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %ptr.d9e: type = ptr_type %C [concrete]
 // CHECK:STDOUT:   %C__carbon_thunk.type: type = fn_type @C__carbon_thunk [concrete]
 // CHECK:STDOUT:   %C__carbon_thunk: %C__carbon_thunk.type = struct_value () [concrete]
@@ -292,7 +292,7 @@ fn F() {
 // CHECK:STDOUT:     import Cpp//...
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %C.decl: type = class_decl @C [concrete = constants.%C] {} {}
-// CHECK:STDOUT:   %.40b: %.d40 = cpp_overload_set_value @<null name> [concrete = constants.%.40b]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.value: %C.C.cpp_overload_set.type = cpp_overload_set_value @C.C.cpp_overload_set [concrete = constants.%C.C.cpp_overload_set.value]
 // CHECK:STDOUT:   %C__carbon_thunk.decl: %C__carbon_thunk.type = fn_decl @C__carbon_thunk [concrete = constants.%C__carbon_thunk] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
@@ -307,7 +307,7 @@ fn F() {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %Cpp.ref.loc8_18: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %C.ref.loc8_21: type = name_ref C, imports.%C.decl [concrete = constants.%C]
-// CHECK:STDOUT:   %C.ref.loc8_23: %.d40 = name_ref C, imports.%.40b [concrete = constants.%.40b]
+// CHECK:STDOUT:   %C.ref.loc8_23: %C.C.cpp_overload_set.type = name_ref C, imports.%C.C.cpp_overload_set.value [concrete = constants.%C.C.cpp_overload_set.value]
 // CHECK:STDOUT:   %.loc8_26.1: ref %C = temporary_storage
 // CHECK:STDOUT:   %addr.loc8_26.1: %ptr.d9e = addr_of %.loc8_26.1
 // CHECK:STDOUT:   %C__carbon_thunk.call: init %empty_tuple.type = call imports.%C__carbon_thunk.decl(%addr.loc8_26.1)
@@ -335,8 +335,8 @@ fn F() {
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
 // CHECK:STDOUT:   %C: type = class_type @C [concrete]
 // CHECK:STDOUT:   %pattern_type.217: type = pattern_type %C [concrete]
-// CHECK:STDOUT:   %.d40: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.40b: %.d40 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.type: type = cpp_overload_set_type @C.C.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.value: %C.C.cpp_overload_set.type = cpp_overload_set_value @C.C.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %int_123.fff: Core.IntLiteral = int_value 123 [concrete]
 // CHECK:STDOUT:   %int_456.010: Core.IntLiteral = int_value 456 [concrete]
 // CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [concrete]
@@ -373,7 +373,7 @@ fn F() {
 // CHECK:STDOUT:     import Cpp//...
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %C.decl: type = class_decl @C [concrete = constants.%C] {} {}
-// CHECK:STDOUT:   %.40b: %.d40 = cpp_overload_set_value @<null name> [concrete = constants.%.40b]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.value: %C.C.cpp_overload_set.type = cpp_overload_set_value @C.C.cpp_overload_set [concrete = constants.%C.C.cpp_overload_set.value]
 // CHECK:STDOUT:   %C__carbon_thunk.decl: %C__carbon_thunk.type = fn_decl @C__carbon_thunk [concrete = constants.%C__carbon_thunk] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
@@ -390,7 +390,7 @@ fn F() {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %Cpp.ref.loc8_18: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %C.ref.loc8_21: type = name_ref C, imports.%C.decl [concrete = constants.%C]
-// CHECK:STDOUT:   %C.ref.loc8_23: %.d40 = name_ref C, imports.%.40b [concrete = constants.%.40b]
+// CHECK:STDOUT:   %C.ref.loc8_23: %C.C.cpp_overload_set.type = name_ref C, imports.%C.C.cpp_overload_set.value [concrete = constants.%C.C.cpp_overload_set.value]
 // CHECK:STDOUT:   %int_123: Core.IntLiteral = int_value 123 [concrete = constants.%int_123.fff]
 // CHECK:STDOUT:   %int_456: Core.IntLiteral = int_value 456 [concrete = constants.%int_456.010]
 // CHECK:STDOUT:   %.loc8_34.1: ref %C = temporary_storage
@@ -434,8 +434,8 @@ fn F() {
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
 // CHECK:STDOUT:   %C: type = class_type @C [concrete]
 // CHECK:STDOUT:   %pattern_type.217: type = pattern_type %C [concrete]
-// CHECK:STDOUT:   %.d40: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.40b: %.d40 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.type: type = cpp_overload_set_type @C.C.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.value: %C.C.cpp_overload_set.type = cpp_overload_set_value @C.C.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %ptr.d9e: type = ptr_type %C [concrete]
 // CHECK:STDOUT:   %C__carbon_thunk.type.65f120.1: type = fn_type @C__carbon_thunk.1 [concrete]
 // CHECK:STDOUT:   %C__carbon_thunk.d98342.1: %C__carbon_thunk.type.65f120.1 = struct_value () [concrete]
@@ -474,7 +474,7 @@ fn F() {
 // CHECK:STDOUT:     import Cpp//...
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %C.decl: type = class_decl @C [concrete = constants.%C] {} {}
-// CHECK:STDOUT:   %.40b: %.d40 = cpp_overload_set_value @<null name> [concrete = constants.%.40b]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.value: %C.C.cpp_overload_set.type = cpp_overload_set_value @C.C.cpp_overload_set [concrete = constants.%C.C.cpp_overload_set.value]
 // CHECK:STDOUT:   %C__carbon_thunk.decl.8acdfe.1: %C__carbon_thunk.type.65f120.1 = fn_decl @C__carbon_thunk.1 [concrete = constants.%C__carbon_thunk.d98342.1] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
@@ -496,7 +496,7 @@ fn F() {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %Cpp.ref.loc8_19: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %C.ref.loc8_22: type = name_ref C, imports.%C.decl [concrete = constants.%C]
-// CHECK:STDOUT:   %C.ref.loc8_24: %.d40 = name_ref C, imports.%.40b [concrete = constants.%.40b]
+// CHECK:STDOUT:   %C.ref.loc8_24: %C.C.cpp_overload_set.type = name_ref C, imports.%C.C.cpp_overload_set.value [concrete = constants.%C.C.cpp_overload_set.value]
 // CHECK:STDOUT:   %.loc8_27.1: ref %C = temporary_storage
 // CHECK:STDOUT:   %addr.loc8_27.1: %ptr.d9e = addr_of %.loc8_27.1
 // CHECK:STDOUT:   %C__carbon_thunk.call.loc8: init %empty_tuple.type = call imports.%C__carbon_thunk.decl.8acdfe.1(%addr.loc8_27.1)
@@ -513,7 +513,7 @@ fn F() {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %Cpp.ref.loc9_19: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %C.ref.loc9_22: type = name_ref C, imports.%C.decl [concrete = constants.%C]
-// CHECK:STDOUT:   %C.ref.loc9_24: %.d40 = name_ref C, imports.%.40b [concrete = constants.%.40b]
+// CHECK:STDOUT:   %C.ref.loc9_24: %C.C.cpp_overload_set.type = name_ref C, imports.%C.C.cpp_overload_set.value [concrete = constants.%C.C.cpp_overload_set.value]
 // CHECK:STDOUT:   %int_123: Core.IntLiteral = int_value 123 [concrete = constants.%int_123.fff]
 // CHECK:STDOUT:   %int_456: Core.IntLiteral = int_value 456 [concrete = constants.%int_456.010]
 // CHECK:STDOUT:   %.loc9_35.1: ref %C = temporary_storage
@@ -564,8 +564,8 @@ fn F() {
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
 // CHECK:STDOUT:   %C: type = class_type @C [concrete]
 // CHECK:STDOUT:   %pattern_type.217: type = pattern_type %C [concrete]
-// CHECK:STDOUT:   %.d40: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.40b: %.d40 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.type: type = cpp_overload_set_type @C.C.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.value: %C.C.cpp_overload_set.type = cpp_overload_set_value @C.C.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %int_8.b85: Core.IntLiteral = int_value 8 [concrete]
 // CHECK:STDOUT:   %int_9.988: Core.IntLiteral = int_value 9 [concrete]
 // CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [concrete]
@@ -604,7 +604,7 @@ fn F() {
 // CHECK:STDOUT:     import Cpp//...
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %C.decl: type = class_decl @C [concrete = constants.%C] {} {}
-// CHECK:STDOUT:   %.40b: %.d40 = cpp_overload_set_value @<null name> [concrete = constants.%.40b]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.value: %C.C.cpp_overload_set.type = cpp_overload_set_value @C.C.cpp_overload_set [concrete = constants.%C.C.cpp_overload_set.value]
 // CHECK:STDOUT:   %C__carbon_thunk.decl.8acdfe.1: %C__carbon_thunk.type.65f120.1 = fn_decl @C__carbon_thunk.1 [concrete = constants.%C__carbon_thunk.d98342.1] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
@@ -626,7 +626,7 @@ fn F() {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %Cpp.ref.loc8_19: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %C.ref.loc8_22: type = name_ref C, imports.%C.decl [concrete = constants.%C]
-// CHECK:STDOUT:   %C.ref.loc8_24: %.d40 = name_ref C, imports.%.40b [concrete = constants.%.40b]
+// CHECK:STDOUT:   %C.ref.loc8_24: %C.C.cpp_overload_set.type = name_ref C, imports.%C.C.cpp_overload_set.value [concrete = constants.%C.C.cpp_overload_set.value]
 // CHECK:STDOUT:   %int_8.loc8: Core.IntLiteral = int_value 8 [concrete = constants.%int_8.b85]
 // CHECK:STDOUT:   %int_9: Core.IntLiteral = int_value 9 [concrete = constants.%int_9.988]
 // CHECK:STDOUT:   %.loc8_31.1: ref %C = temporary_storage
@@ -659,7 +659,7 @@ fn F() {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %Cpp.ref.loc9_19: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %C.ref.loc9_22: type = name_ref C, imports.%C.decl [concrete = constants.%C]
-// CHECK:STDOUT:   %C.ref.loc9_24: %.d40 = name_ref C, imports.%.40b [concrete = constants.%.40b]
+// CHECK:STDOUT:   %C.ref.loc9_24: %C.C.cpp_overload_set.type = name_ref C, imports.%C.C.cpp_overload_set.value [concrete = constants.%C.C.cpp_overload_set.value]
 // CHECK:STDOUT:   %int_8.loc9: Core.IntLiteral = int_value 8 [concrete = constants.%int_8.b85]
 // CHECK:STDOUT:   %.loc9_28.1: ref %C = temporary_storage
 // CHECK:STDOUT:   %impl.elem0.loc9: %.1df = impl_witness_access constants.%ImplicitAs.impl_witness.204, element0 [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.0f0]
@@ -702,8 +702,8 @@ fn F() {
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
 // CHECK:STDOUT:   %C: type = class_type @C [concrete]
 // CHECK:STDOUT:   %pattern_type.217: type = pattern_type %C [concrete]
-// CHECK:STDOUT:   %.d40: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.40b: %.d40 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.type: type = cpp_overload_set_type @C.C.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.value: %C.C.cpp_overload_set.type = cpp_overload_set_value @C.C.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %int_123.fff: Core.IntLiteral = int_value 123 [concrete]
 // CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [concrete]
 // CHECK:STDOUT:   %i32: type = class_type @Int, @Int(%int_32) [concrete]
@@ -753,7 +753,7 @@ fn F() {
 // CHECK:STDOUT:     import Cpp//...
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %C.decl: type = class_decl @C [concrete = constants.%C] {} {}
-// CHECK:STDOUT:   %.40b: %.d40 = cpp_overload_set_value @<null name> [concrete = constants.%.40b]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.value: %C.C.cpp_overload_set.type = cpp_overload_set_value @C.C.cpp_overload_set [concrete = constants.%C.C.cpp_overload_set.value]
 // CHECK:STDOUT:   %C__carbon_thunk.decl.8acdfe.1: %C__carbon_thunk.type.65f120.1 = fn_decl @C__carbon_thunk.1 [concrete = constants.%C__carbon_thunk.d98342.1] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
@@ -784,7 +784,7 @@ fn F() {
 // CHECK:STDOUT:   %c1.var: ref %C = var %c1.var_patt
 // CHECK:STDOUT:   %Cpp.ref.loc8_19: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %C.ref.loc8_22: type = name_ref C, imports.%C.decl [concrete = constants.%C]
-// CHECK:STDOUT:   %C.ref.loc8_24: %.d40 = name_ref C, imports.%.40b [concrete = constants.%.40b]
+// CHECK:STDOUT:   %C.ref.loc8_24: %C.C.cpp_overload_set.type = name_ref C, imports.%C.C.cpp_overload_set.value [concrete = constants.%C.C.cpp_overload_set.value]
 // CHECK:STDOUT:   %int_123: Core.IntLiteral = int_value 123 [concrete = constants.%int_123.fff]
 // CHECK:STDOUT:   %.loc8_3.1: ref %C = splice_block %c1.var {}
 // CHECK:STDOUT:   %impl.elem0.loc8: %.1df = impl_witness_access constants.%ImplicitAs.impl_witness.204, element0 [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.0f0]
@@ -810,7 +810,7 @@ fn F() {
 // CHECK:STDOUT:   %c2.var: ref %C = var %c2.var_patt
 // CHECK:STDOUT:   %Cpp.ref.loc9_19: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %C.ref.loc9_22: type = name_ref C, imports.%C.decl [concrete = constants.%C]
-// CHECK:STDOUT:   %C.ref.loc9_24: %.d40 = name_ref C, imports.%.40b [concrete = constants.%.40b]
+// CHECK:STDOUT:   %C.ref.loc9_24: %C.C.cpp_overload_set.type = name_ref C, imports.%C.C.cpp_overload_set.value [concrete = constants.%C.C.cpp_overload_set.value]
 // CHECK:STDOUT:   %true: bool = bool_literal true [concrete = constants.%true]
 // CHECK:STDOUT:   %.loc9_3.1: ref %C = splice_block %c2.var {}
 // CHECK:STDOUT:   %.loc9_27.1: ref bool = temporary_storage
@@ -835,7 +835,7 @@ fn F() {
 // CHECK:STDOUT:   %c3.var: ref %C = var %c3.var_patt
 // CHECK:STDOUT:   %Cpp.ref.loc10_19: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %C.ref.loc10_22: type = name_ref C, imports.%C.decl [concrete = constants.%C]
-// CHECK:STDOUT:   %C.ref.loc10_24: %.d40 = name_ref C, imports.%.40b [concrete = constants.%.40b]
+// CHECK:STDOUT:   %C.ref.loc10_24: %C.C.cpp_overload_set.type = name_ref C, imports.%C.C.cpp_overload_set.value [concrete = constants.%C.C.cpp_overload_set.value]
 // CHECK:STDOUT:   %c1.ref: ref %C = name_ref c1, %c1
 // CHECK:STDOUT:   %addr.loc10_27: %ptr.d9e = addr_of %c1.ref
 // CHECK:STDOUT:   %.loc10_3.1: ref %C = splice_block %c3.var {}
@@ -885,8 +885,8 @@ fn F() {
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
 // CHECK:STDOUT:   %C: type = class_type @C [concrete]
 // CHECK:STDOUT:   %pattern_type.217: type = pattern_type %C [concrete]
-// CHECK:STDOUT:   %.d40: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.40b: %.d40 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.type: type = cpp_overload_set_type @C.C.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.value: %C.C.cpp_overload_set.type = cpp_overload_set_value @C.C.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %int_8.b85: Core.IntLiteral = int_value 8 [concrete]
 // CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [concrete]
 // CHECK:STDOUT:   %i32: type = class_type @Int, @Int(%int_32) [concrete]
@@ -931,7 +931,7 @@ fn F() {
 // CHECK:STDOUT:     import Cpp//...
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %C.decl: type = class_decl @C [concrete = constants.%C] {} {}
-// CHECK:STDOUT:   %.40b: %.d40 = cpp_overload_set_value @<null name> [concrete = constants.%.40b]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.value: %C.C.cpp_overload_set.type = cpp_overload_set_value @C.C.cpp_overload_set [concrete = constants.%C.C.cpp_overload_set.value]
 // CHECK:STDOUT:   %C__carbon_thunk.decl: %C__carbon_thunk.type = fn_decl @C__carbon_thunk [concrete = constants.%C__carbon_thunk] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
@@ -950,7 +950,7 @@ fn F() {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %Cpp.ref.loc8_19: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %C.ref.loc8_22: type = name_ref C, imports.%C.decl [concrete = constants.%C]
-// CHECK:STDOUT:   %C.ref.loc8_24: %.d40 = name_ref C, imports.%.40b [concrete = constants.%.40b]
+// CHECK:STDOUT:   %C.ref.loc8_24: %C.C.cpp_overload_set.type = name_ref C, imports.%C.C.cpp_overload_set.value [concrete = constants.%C.C.cpp_overload_set.value]
 // CHECK:STDOUT:   %int_8.loc8: Core.IntLiteral = int_value 8 [concrete = constants.%int_8.b85]
 // CHECK:STDOUT:   %.loc8_28.1: ref %C = temporary_storage
 // CHECK:STDOUT:   %impl.elem0.loc8: %.1df = impl_witness_access constants.%ImplicitAs.impl_witness.204, element0 [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.0f0]
@@ -1005,8 +1005,8 @@ fn F() {
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
 // CHECK:STDOUT:   %C: type = class_type @C [concrete]
 // CHECK:STDOUT:   %pattern_type.217: type = pattern_type %C [concrete]
-// CHECK:STDOUT:   %.d40: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.40b: %.d40 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.type: type = cpp_overload_set_type @C.C.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.value: %C.C.cpp_overload_set.type = cpp_overload_set_value @C.C.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %int_8.b85: Core.IntLiteral = int_value 8 [concrete]
 // CHECK:STDOUT:   %int_9.988: Core.IntLiteral = int_value 9 [concrete]
 // CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [concrete]
@@ -1057,7 +1057,7 @@ fn F() {
 // CHECK:STDOUT:     import Cpp//...
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %C.decl: type = class_decl @C [concrete = constants.%C] {} {}
-// CHECK:STDOUT:   %.40b: %.d40 = cpp_overload_set_value @<null name> [concrete = constants.%.40b]
+// CHECK:STDOUT:   %C.C.cpp_overload_set.value: %C.C.cpp_overload_set.type = cpp_overload_set_value @C.C.cpp_overload_set [concrete = constants.%C.C.cpp_overload_set.value]
 // CHECK:STDOUT:   %C__carbon_thunk.decl.8acdfe.1: %C__carbon_thunk.type.65f120.1 = fn_decl @C__carbon_thunk.1 [concrete = constants.%C__carbon_thunk.d98342.1] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
@@ -1081,7 +1081,7 @@ fn F() {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %Cpp.ref.loc8_19: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %C.ref.loc8_22: type = name_ref C, imports.%C.decl [concrete = constants.%C]
-// CHECK:STDOUT:   %C.ref.loc8_24: %.d40 = name_ref C, imports.%.40b [concrete = constants.%.40b]
+// CHECK:STDOUT:   %C.ref.loc8_24: %C.C.cpp_overload_set.type = name_ref C, imports.%C.C.cpp_overload_set.value [concrete = constants.%C.C.cpp_overload_set.value]
 // CHECK:STDOUT:   %int_8.loc8: Core.IntLiteral = int_value 8 [concrete = constants.%int_8.b85]
 // CHECK:STDOUT:   %int_9: Core.IntLiteral = int_value 9 [concrete = constants.%int_9.988]
 // CHECK:STDOUT:   %.loc8_31.1: ref %C = temporary_storage
@@ -1114,7 +1114,7 @@ fn F() {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %Cpp.ref.loc9_19: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %C.ref.loc9_22: type = name_ref C, imports.%C.decl [concrete = constants.%C]
-// CHECK:STDOUT:   %C.ref.loc9_24: %.d40 = name_ref C, imports.%.40b [concrete = constants.%.40b]
+// CHECK:STDOUT:   %C.ref.loc9_24: %C.C.cpp_overload_set.type = name_ref C, imports.%C.C.cpp_overload_set.value [concrete = constants.%C.C.cpp_overload_set.value]
 // CHECK:STDOUT:   %int_8.loc9: Core.IntLiteral = int_value 8 [concrete = constants.%int_8.b85]
 // CHECK:STDOUT:   %.loc9_28.1: ref %C = temporary_storage
 // CHECK:STDOUT:   %impl.elem0.loc9: %.1df = impl_witness_access constants.%ImplicitAs.impl_witness.204, element0 [concrete = constants.%Core.IntLiteral.as.ImplicitAs.impl.Convert.0f0]
@@ -207,46 +207,46 @@ fn Call(e: Cpp.ExplicitObjectParam, n: i32, a: Cpp.Another) {
 // CHECK:STDOUT:   %HasQualifiers: type = class_type @HasQualifiers [concrete]
 // CHECK:STDOUT:   %ptr.ec3: type = ptr_type %HasQualifiers [concrete]
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
-// CHECK:STDOUT:   %.602: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.ce8: %.602 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %HasQualifiers.const_this.cpp_overload_set.type: type = cpp_overload_set_type @HasQualifiers.const_this.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %HasQualifiers.const_this.cpp_overload_set.value: %HasQualifiers.const_this.cpp_overload_set.type = cpp_overload_set_value @HasQualifiers.const_this.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %const: type = const_type %HasQualifiers [concrete]
 // CHECK:STDOUT:   %ptr.2cb: type = ptr_type %const [concrete]
 // CHECK:STDOUT:   %const_this__carbon_thunk.type: type = fn_type @const_this__carbon_thunk [concrete]
 // CHECK:STDOUT:   %const_this__carbon_thunk: %const_this__carbon_thunk.type = struct_value () [concrete]
-// CHECK:STDOUT:   %.bf0: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.667: %.bf0 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %HasQualifiers.const_ref_this.cpp_overload_set.type: type = cpp_overload_set_type @HasQualifiers.const_ref_this.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %HasQualifiers.const_ref_this.cpp_overload_set.value: %HasQualifiers.const_ref_this.cpp_overload_set.type = cpp_overload_set_value @HasQualifiers.const_ref_this.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %const_ref_this__carbon_thunk.type: type = fn_type @const_ref_this__carbon_thunk [concrete]
 // CHECK:STDOUT:   %const_ref_this__carbon_thunk: %const_ref_this__carbon_thunk.type = struct_value () [concrete]
-// CHECK:STDOUT:   %.64b: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.646: %.64b = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %HasQualifiers.plain.cpp_overload_set.type: type = cpp_overload_set_type @HasQualifiers.plain.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %HasQualifiers.plain.cpp_overload_set.value: %HasQualifiers.plain.cpp_overload_set.type = cpp_overload_set_value @HasQualifiers.plain.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %HasQualifiers.plain.type: type = fn_type @HasQualifiers.plain [concrete]
 // CHECK:STDOUT:   %HasQualifiers.plain: %HasQualifiers.plain.type = struct_value () [concrete]
-// CHECK:STDOUT:   %.352: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.145: %.352 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %HasQualifiers.ref_this.cpp_overload_set.type: type = cpp_overload_set_type @HasQualifiers.ref_this.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %HasQualifiers.ref_this.cpp_overload_set.value: %HasQualifiers.ref_this.cpp_overload_set.type = cpp_overload_set_value @HasQualifiers.ref_this.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %HasQualifiers.ref_this.type: type = fn_type @HasQualifiers.ref_this [concrete]
 // CHECK:STDOUT:   %HasQualifiers.ref_this: %HasQualifiers.ref_this.type = struct_value () [concrete]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: imports {
-// CHECK:STDOUT:   %.ce8: %.602 = cpp_overload_set_value @<null name> [concrete = constants.%.ce8]
+// CHECK:STDOUT:   %HasQualifiers.const_this.cpp_overload_set.value: %HasQualifiers.const_this.cpp_overload_set.type = cpp_overload_set_value @HasQualifiers.const_this.cpp_overload_set [concrete = constants.%HasQualifiers.const_this.cpp_overload_set.value]
 // CHECK:STDOUT:   %const_this__carbon_thunk.decl: %const_this__carbon_thunk.type = fn_decl @const_this__carbon_thunk [concrete = constants.%const_this__carbon_thunk] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %.667: %.bf0 = cpp_overload_set_value @<null name> [concrete = constants.%.667]
+// CHECK:STDOUT:   %HasQualifiers.const_ref_this.cpp_overload_set.value: %HasQualifiers.const_ref_this.cpp_overload_set.type = cpp_overload_set_value @HasQualifiers.const_ref_this.cpp_overload_set [concrete = constants.%HasQualifiers.const_ref_this.cpp_overload_set.value]
 // CHECK:STDOUT:   %const_ref_this__carbon_thunk.decl: %const_ref_this__carbon_thunk.type = fn_decl @const_ref_this__carbon_thunk [concrete = constants.%const_ref_this__carbon_thunk] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %.646: %.64b = cpp_overload_set_value @<null name> [concrete = constants.%.646]
+// CHECK:STDOUT:   %HasQualifiers.plain.cpp_overload_set.value: %HasQualifiers.plain.cpp_overload_set.type = cpp_overload_set_value @HasQualifiers.plain.cpp_overload_set [concrete = constants.%HasQualifiers.plain.cpp_overload_set.value]
 // CHECK:STDOUT:   %HasQualifiers.plain.decl: %HasQualifiers.plain.type = fn_decl @HasQualifiers.plain [concrete = constants.%HasQualifiers.plain] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %.145: %.352 = cpp_overload_set_value @<null name> [concrete = constants.%.145]
+// CHECK:STDOUT:   %HasQualifiers.ref_this.cpp_overload_set.value: %HasQualifiers.ref_this.cpp_overload_set.type = cpp_overload_set_value @HasQualifiers.ref_this.cpp_overload_set [concrete = constants.%HasQualifiers.ref_this.cpp_overload_set.value]
 // CHECK:STDOUT:   %HasQualifiers.ref_this.decl: %HasQualifiers.ref_this.type = fn_decl @HasQualifiers.ref_this [concrete = constants.%HasQualifiers.ref_this] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
@@ -257,7 +257,7 @@ fn Call(e: Cpp.ExplicitObjectParam, n: i32, a: Cpp.Another) {
 // CHECK:STDOUT: fn @F(%v.param: %HasQualifiers, %p.param: %ptr.ec3) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %v.ref.loc8: %HasQualifiers = name_ref v, %v
-// CHECK:STDOUT:   %const_this.ref.loc8: %.602 = name_ref const_this, imports.%.ce8 [concrete = constants.%.ce8]
+// CHECK:STDOUT:   %const_this.ref.loc8: %HasQualifiers.const_this.cpp_overload_set.type = name_ref const_this, imports.%HasQualifiers.const_this.cpp_overload_set.value [concrete = constants.%HasQualifiers.const_this.cpp_overload_set.value]
 // CHECK:STDOUT:   %bound_method.loc8: <bound method> = bound_method %v.ref.loc8, %const_this.ref.loc8
 // CHECK:STDOUT:   %.loc8_3: ref %HasQualifiers = value_as_ref %v.ref.loc8
 // CHECK:STDOUT:   %addr.loc8: %ptr.ec3 = addr_of %.loc8_3
@@ -265,7 +265,7 @@ fn Call(e: Cpp.ExplicitObjectParam, n: i32, a: Cpp.Another) {
 // CHECK:STDOUT:   %.loc8_16.2: %ptr.2cb = converted %addr.loc8, %.loc8_16.1
 // CHECK:STDOUT:   %const_this__carbon_thunk.call.loc8: init %empty_tuple.type = call imports.%const_this__carbon_thunk.decl(%.loc8_16.2)
 // CHECK:STDOUT:   %v.ref.loc9: %HasQualifiers = name_ref v, %v
-// CHECK:STDOUT:   %const_ref_this.ref.loc9: %.bf0 = name_ref const_ref_this, imports.%.667 [concrete = constants.%.667]
+// CHECK:STDOUT:   %const_ref_this.ref.loc9: %HasQualifiers.const_ref_this.cpp_overload_set.type = name_ref const_ref_this, imports.%HasQualifiers.const_ref_this.cpp_overload_set.value [concrete = constants.%HasQualifiers.const_ref_this.cpp_overload_set.value]
 // CHECK:STDOUT:   %bound_method.loc9: <bound method> = bound_method %v.ref.loc9, %const_ref_this.ref.loc9
 // CHECK:STDOUT:   %.loc9_3: ref %HasQualifiers = value_as_ref %v.ref.loc9
 // CHECK:STDOUT:   %addr.loc9: %ptr.ec3 = addr_of %.loc9_3
@@ -274,19 +274,19 @@ fn Call(e: Cpp.ExplicitObjectParam, n: i32, a: Cpp.Another) {
 // CHECK:STDOUT:   %const_ref_this__carbon_thunk.call.loc9: init %empty_tuple.type = call imports.%const_ref_this__carbon_thunk.decl(%.loc9_20.2)
 // CHECK:STDOUT:   %p.ref.loc11: %ptr.ec3 = name_ref p, %p
 // CHECK:STDOUT:   %.loc11: ref %HasQualifiers = deref %p.ref.loc11
-// CHECK:STDOUT:   %plain.ref: %.64b = name_ref plain, imports.%.646 [concrete = constants.%.646]
+// CHECK:STDOUT:   %plain.ref: %HasQualifiers.plain.cpp_overload_set.type = name_ref plain, imports.%HasQualifiers.plain.cpp_overload_set.value [concrete = constants.%HasQualifiers.plain.cpp_overload_set.value]
 // CHECK:STDOUT:   %bound_method.loc11: <bound method> = bound_method %.loc11, %plain.ref
 // CHECK:STDOUT:   %addr.loc11: %ptr.ec3 = addr_of %.loc11
 // CHECK:STDOUT:   %HasQualifiers.plain.call: init %empty_tuple.type = call imports.%HasQualifiers.plain.decl(%addr.loc11)
 // CHECK:STDOUT:   %p.ref.loc12: %ptr.ec3 = name_ref p, %p
 // CHECK:STDOUT:   %.loc12: ref %HasQualifiers = deref %p.ref.loc12
-// CHECK:STDOUT:   %ref_this.ref: %.352 = name_ref ref_this, imports.%.145 [concrete = constants.%.145]
+// CHECK:STDOUT:   %ref_this.ref: %HasQualifiers.ref_this.cpp_overload_set.type = name_ref ref_this, imports.%HasQualifiers.ref_this.cpp_overload_set.value [concrete = constants.%HasQualifiers.ref_this.cpp_overload_set.value]
 // CHECK:STDOUT:   %bound_method.loc12: <bound method> = bound_method %.loc12, %ref_this.ref
 // CHECK:STDOUT:   %addr.loc12: %ptr.ec3 = addr_of %.loc12
 // CHECK:STDOUT:   %HasQualifiers.ref_this.call: init %empty_tuple.type = call imports.%HasQualifiers.ref_this.decl(%addr.loc12)
 // CHECK:STDOUT:   %p.ref.loc13: %ptr.ec3 = name_ref p, %p
 // CHECK:STDOUT:   %.loc13_4.1: ref %HasQualifiers = deref %p.ref.loc13
-// CHECK:STDOUT:   %const_this.ref.loc13: %.602 = name_ref const_this, imports.%.ce8 [concrete = constants.%.ce8]
+// CHECK:STDOUT:   %const_this.ref.loc13: %HasQualifiers.const_this.cpp_overload_set.type = name_ref const_this, imports.%HasQualifiers.const_this.cpp_overload_set.value [concrete = constants.%HasQualifiers.const_this.cpp_overload_set.value]
 // CHECK:STDOUT:   %bound_method.loc13: <bound method> = bound_method %.loc13_4.1, %const_this.ref.loc13
 // CHECK:STDOUT:   %.loc13_4.2: %HasQualifiers = bind_value %.loc13_4.1
 // CHECK:STDOUT:   %.loc13_4.3: ref %HasQualifiers = value_as_ref %.loc13_4.2
@@ -296,7 +296,7 @@ fn Call(e: Cpp.ExplicitObjectParam, n: i32, a: Cpp.Another) {
 // CHECK:STDOUT:   %const_this__carbon_thunk.call.loc13: init %empty_tuple.type = call imports.%const_this__carbon_thunk.decl(%.loc13_17.2)
 // CHECK:STDOUT:   %p.ref.loc14: %ptr.ec3 = name_ref p, %p
 // CHECK:STDOUT:   %.loc14_4.1: ref %HasQualifiers = deref %p.ref.loc14
-// CHECK:STDOUT:   %const_ref_this.ref.loc14: %.bf0 = name_ref const_ref_this, imports.%.667 [concrete = constants.%.667]
+// CHECK:STDOUT:   %const_ref_this.ref.loc14: %HasQualifiers.const_ref_this.cpp_overload_set.type = name_ref const_ref_this, imports.%HasQualifiers.const_ref_this.cpp_overload_set.value [concrete = constants.%HasQualifiers.const_ref_this.cpp_overload_set.value]
 // CHECK:STDOUT:   %bound_method.loc14: <bound method> = bound_method %.loc14_4.1, %const_ref_this.ref.loc14
 // CHECK:STDOUT:   %.loc14_4.2: %HasQualifiers = bind_value %.loc14_4.1
 // CHECK:STDOUT:   %.loc14_4.3: ref %HasQualifiers = value_as_ref %.loc14_4.2
@@ -316,8 +316,8 @@ fn Call(e: Cpp.ExplicitObjectParam, n: i32, a: Cpp.Another) {
 // CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [concrete]
 // CHECK:STDOUT:   %i32: type = class_type @Int, @Int(%int_32) [concrete]
 // CHECK:STDOUT:   %pattern_type.7ce: type = pattern_type %i32 [concrete]
-// CHECK:STDOUT:   %.4ab: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.570: %.4ab = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %HasQualifiers.F.cpp_overload_set.type: type = cpp_overload_set_type @HasQualifiers.F.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %HasQualifiers.F.cpp_overload_set.value: %HasQualifiers.F.cpp_overload_set.type = cpp_overload_set_value @HasQualifiers.F.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %const: type = const_type %HasQualifiers [concrete]
 // CHECK:STDOUT:   %ptr.2cb: type = ptr_type %const [concrete]
 // CHECK:STDOUT:   %F__carbon_thunk.type: type = fn_type @F__carbon_thunk [concrete]
@@ -337,7 +337,7 @@ fn Call(e: Cpp.ExplicitObjectParam, n: i32, a: Cpp.Another) {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: imports {
-// CHECK:STDOUT:   %.570: %.4ab = cpp_overload_set_value @<null name> [concrete = constants.%.570]
+// CHECK:STDOUT:   %HasQualifiers.F.cpp_overload_set.value: %HasQualifiers.F.cpp_overload_set.type = cpp_overload_set_value @HasQualifiers.F.cpp_overload_set [concrete = constants.%HasQualifiers.F.cpp_overload_set.value]
 // CHECK:STDOUT:   %F__carbon_thunk.decl: %F__carbon_thunk.type = fn_decl @F__carbon_thunk [concrete = constants.%F__carbon_thunk] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
@@ -358,7 +358,7 @@ fn Call(e: Cpp.ExplicitObjectParam, n: i32, a: Cpp.Another) {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %a.var: ref %i32 = var %a.var_patt
 // CHECK:STDOUT:   %v.ref: %HasQualifiers = name_ref v, %v
-// CHECK:STDOUT:   %F.ref.loc8: %.4ab = name_ref F, imports.%.570 [concrete = constants.%.570]
+// CHECK:STDOUT:   %F.ref.loc8: %HasQualifiers.F.cpp_overload_set.type = name_ref F, imports.%HasQualifiers.F.cpp_overload_set.value [concrete = constants.%HasQualifiers.F.cpp_overload_set.value]
 // CHECK:STDOUT:   %bound_method.loc8_17: <bound method> = bound_method %v.ref, %F.ref.loc8
 // CHECK:STDOUT:   %.loc8_16: ref %HasQualifiers = value_as_ref %v.ref
 // CHECK:STDOUT:   %addr.loc8_20: %ptr.ec3 = addr_of %.loc8_16
@@ -378,7 +378,7 @@ fn Call(e: Cpp.ExplicitObjectParam, n: i32, a: Cpp.Another) {
 // CHECK:STDOUT:   %b.var: ref %ptr.235 = var %b.var_patt
 // CHECK:STDOUT:   %p.ref: %ptr.ec3 = name_ref p, %p
 // CHECK:STDOUT:   %.loc9_18: ref %HasQualifiers = deref %p.ref
-// CHECK:STDOUT:   %F.ref.loc9: %.4ab = name_ref F, imports.%.570 [concrete = constants.%.570]
+// CHECK:STDOUT:   %F.ref.loc9: %HasQualifiers.F.cpp_overload_set.type = name_ref F, imports.%HasQualifiers.F.cpp_overload_set.value [concrete = constants.%HasQualifiers.F.cpp_overload_set.value]
 // CHECK:STDOUT:   %bound_method.loc9_18: <bound method> = bound_method %.loc9_18, %F.ref.loc9
 // CHECK:STDOUT:   %addr.loc9_18: %ptr.ec3 = addr_of %.loc9_18
 // CHECK:STDOUT:   %HasQualifiers.F.call: init %ptr.235 = call imports.%HasQualifiers.F.decl.f862ea.2(%addr.loc9_18)
@@ -414,17 +414,17 @@ fn Call(e: Cpp.ExplicitObjectParam, n: i32, a: Cpp.Another) {
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
 // CHECK:STDOUT:   %i32: type = class_type @Int, @Int(%int_32) [concrete]
 // CHECK:STDOUT:   %Another: type = class_type @Another [concrete]
-// CHECK:STDOUT:   %.3e2: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.037: %.3e2 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %ExplicitObjectParam.F.cpp_overload_set.type: type = cpp_overload_set_type @ExplicitObjectParam.F.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %ExplicitObjectParam.F.cpp_overload_set.value: %ExplicitObjectParam.F.cpp_overload_set.type = cpp_overload_set_value @ExplicitObjectParam.F.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %ptr.7f5: type = ptr_type %ExplicitObjectParam [concrete]
 // CHECK:STDOUT:   %F__carbon_thunk.type: type = fn_type @F__carbon_thunk [concrete]
 // CHECK:STDOUT:   %F__carbon_thunk: %F__carbon_thunk.type = struct_value () [concrete]
-// CHECK:STDOUT:   %.d44: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.151: %.d44 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %ExplicitObjectParam.G.cpp_overload_set.type: type = cpp_overload_set_type @ExplicitObjectParam.G.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %ExplicitObjectParam.G.cpp_overload_set.value: %ExplicitObjectParam.G.cpp_overload_set.type = cpp_overload_set_value @ExplicitObjectParam.G.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %ExplicitObjectParam.G.type: type = fn_type @ExplicitObjectParam.G [concrete]
 // CHECK:STDOUT:   %ExplicitObjectParam.G: %ExplicitObjectParam.G.type = struct_value () [concrete]
-// CHECK:STDOUT:   %.9fb: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.34a: %.9fb = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %ExplicitObjectParam.H.cpp_overload_set.type: type = cpp_overload_set_type @ExplicitObjectParam.H.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %ExplicitObjectParam.H.cpp_overload_set.value: %ExplicitObjectParam.H.cpp_overload_set.type = cpp_overload_set_value @ExplicitObjectParam.H.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %ptr.289: type = ptr_type %Another [concrete]
 // CHECK:STDOUT:   %H__carbon_thunk.type: type = fn_type @H__carbon_thunk [concrete]
 // CHECK:STDOUT:   %H__carbon_thunk: %H__carbon_thunk.type = struct_value () [concrete]
@@ -438,19 +438,19 @@ fn Call(e: Cpp.ExplicitObjectParam, n: i32, a: Cpp.Another) {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %ExplicitObjectParam.decl: type = class_decl @ExplicitObjectParam [concrete = constants.%ExplicitObjectParam] {} {}
 // CHECK:STDOUT:   %Another.decl: type = class_decl @Another [concrete = constants.%Another] {} {}
-// CHECK:STDOUT:   %.037: %.3e2 = cpp_overload_set_value @<null name> [concrete = constants.%.037]
+// CHECK:STDOUT:   %ExplicitObjectParam.F.cpp_overload_set.value: %ExplicitObjectParam.F.cpp_overload_set.type = cpp_overload_set_value @ExplicitObjectParam.F.cpp_overload_set [concrete = constants.%ExplicitObjectParam.F.cpp_overload_set.value]
 // CHECK:STDOUT:   %F__carbon_thunk.decl: %F__carbon_thunk.type = fn_decl @F__carbon_thunk [concrete = constants.%F__carbon_thunk] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %.151: %.d44 = cpp_overload_set_value @<null name> [concrete = constants.%.151]
+// CHECK:STDOUT:   %ExplicitObjectParam.G.cpp_overload_set.value: %ExplicitObjectParam.G.cpp_overload_set.type = cpp_overload_set_value @ExplicitObjectParam.G.cpp_overload_set [concrete = constants.%ExplicitObjectParam.G.cpp_overload_set.value]
 // CHECK:STDOUT:   %ExplicitObjectParam.G.decl: %ExplicitObjectParam.G.type = fn_decl @ExplicitObjectParam.G [concrete = constants.%ExplicitObjectParam.G] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %.34a: %.9fb = cpp_overload_set_value @<null name> [concrete = constants.%.34a]
+// CHECK:STDOUT:   %ExplicitObjectParam.H.cpp_overload_set.value: %ExplicitObjectParam.H.cpp_overload_set.type = cpp_overload_set_value @ExplicitObjectParam.H.cpp_overload_set [concrete = constants.%ExplicitObjectParam.H.cpp_overload_set.value]
 // CHECK:STDOUT:   %H__carbon_thunk.decl: %H__carbon_thunk.type = fn_decl @H__carbon_thunk [concrete = constants.%H__carbon_thunk] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
@@ -461,7 +461,7 @@ fn Call(e: Cpp.ExplicitObjectParam, n: i32, a: Cpp.Another) {
 // CHECK:STDOUT: fn @Call(%e.param: %ExplicitObjectParam, %n.param: %i32, %a.param: %Another) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %e.ref: %ExplicitObjectParam = name_ref e, %e
-// CHECK:STDOUT:   %F.ref: %.3e2 = name_ref F, imports.%.037 [concrete = constants.%.037]
+// CHECK:STDOUT:   %F.ref: %ExplicitObjectParam.F.cpp_overload_set.type = name_ref F, imports.%ExplicitObjectParam.F.cpp_overload_set.value [concrete = constants.%ExplicitObjectParam.F.cpp_overload_set.value]
 // CHECK:STDOUT:   %bound_method.loc8: <bound method> = bound_method %e.ref, %F.ref
 // CHECK:STDOUT:   %.loc8: ref %ExplicitObjectParam = value_as_ref %e.ref
 // CHECK:STDOUT:   %addr.loc8: %ptr.7f5 = addr_of %.loc8
@@ -469,13 +469,13 @@ fn Call(e: Cpp.ExplicitObjectParam, n: i32, a: Cpp.Another) {
 // CHECK:STDOUT:   %n.ref: %i32 = name_ref n, %n
 // CHECK:STDOUT:   %Cpp.ref.loc9: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %ExplicitObjectParam.ref.loc9: type = name_ref ExplicitObjectParam, imports.%ExplicitObjectParam.decl [concrete = constants.%ExplicitObjectParam]
-// CHECK:STDOUT:   %G.ref: %.d44 = name_ref G, imports.%.151 [concrete = constants.%.151]
+// CHECK:STDOUT:   %G.ref: %ExplicitObjectParam.G.cpp_overload_set.type = name_ref G, imports.%ExplicitObjectParam.G.cpp_overload_set.value [concrete = constants.%ExplicitObjectParam.G.cpp_overload_set.value]
 // CHECK:STDOUT:   %bound_method.loc9: <bound method> = bound_method %n.ref, %G.ref
 // CHECK:STDOUT:   %ExplicitObjectParam.G.call: init %empty_tuple.type = call imports.%ExplicitObjectParam.G.decl(%n.ref)
 // CHECK:STDOUT:   %a.ref: %Another = name_ref a, %a
 // CHECK:STDOUT:   %Cpp.ref.loc10: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %ExplicitObjectParam.ref.loc10: type = name_ref ExplicitObjectParam, imports.%ExplicitObjectParam.decl [concrete = constants.%ExplicitObjectParam]
-// CHECK:STDOUT:   %H.ref: %.9fb = name_ref H, imports.%.34a [concrete = constants.%.34a]
+// CHECK:STDOUT:   %H.ref: %ExplicitObjectParam.H.cpp_overload_set.type = name_ref H, imports.%ExplicitObjectParam.H.cpp_overload_set.value [concrete = constants.%ExplicitObjectParam.H.cpp_overload_set.value]
 // CHECK:STDOUT:   %bound_method.loc10: <bound method> = bound_method %a.ref, %H.ref
 // CHECK:STDOUT:   %.loc10: ref %Another = value_as_ref %a.ref
 // CHECK:STDOUT:   %addr.loc10: %ptr.289 = addr_of %.loc10
@@ -491,8 +491,8 @@ fn Call(e: Cpp.ExplicitObjectParam, n: i32, a: Cpp.Another) {
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
 // CHECK:STDOUT:   %i32: type = class_type @Int, @Int(%int_32) [concrete]
 // CHECK:STDOUT:   %Another: type = class_type @Another [concrete]
-// CHECK:STDOUT:   %.3e2: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.037: %.3e2 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %ExplicitObjectParam.F.cpp_overload_set.type: type = cpp_overload_set_type @ExplicitObjectParam.F.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %ExplicitObjectParam.F.cpp_overload_set.value: %ExplicitObjectParam.F.cpp_overload_set.type = cpp_overload_set_value @ExplicitObjectParam.F.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %ptr.7f5: type = ptr_type %ExplicitObjectParam [concrete]
 // CHECK:STDOUT:   %F__carbon_thunk.type.eda1ac.1: type = fn_type @F__carbon_thunk.1 [concrete]
 // CHECK:STDOUT:   %F__carbon_thunk.0cd6a8.1: %F__carbon_thunk.type.eda1ac.1 = struct_value () [concrete]
@@ -511,7 +511,7 @@ fn Call(e: Cpp.ExplicitObjectParam, n: i32, a: Cpp.Another) {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %ExplicitObjectParam.decl: type = class_decl @ExplicitObjectParam [concrete = constants.%ExplicitObjectParam] {} {}
 // CHECK:STDOUT:   %Another.decl: type = class_decl @Another [concrete = constants.%Another] {} {}
-// CHECK:STDOUT:   %.037: %.3e2 = cpp_overload_set_value @<null name> [concrete = constants.%.037]
+// CHECK:STDOUT:   %ExplicitObjectParam.F.cpp_overload_set.value: %ExplicitObjectParam.F.cpp_overload_set.type = cpp_overload_set_value @ExplicitObjectParam.F.cpp_overload_set [concrete = constants.%ExplicitObjectParam.F.cpp_overload_set.value]
 // CHECK:STDOUT:   %F__carbon_thunk.decl.e1b8ec.1: %F__carbon_thunk.type.eda1ac.1 = fn_decl @F__carbon_thunk.1 [concrete = constants.%F__carbon_thunk.0cd6a8.1] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
@@ -532,7 +532,7 @@ fn Call(e: Cpp.ExplicitObjectParam, n: i32, a: Cpp.Another) {
 // CHECK:STDOUT: fn @Call(%e.param: %ExplicitObjectParam, %n.param: %i32, %a.param: %Another) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %e.ref: %ExplicitObjectParam = name_ref e, %e
-// CHECK:STDOUT:   %F.ref.loc8: %.3e2 = name_ref F, imports.%.037 [concrete = constants.%.037]
+// CHECK:STDOUT:   %F.ref.loc8: %ExplicitObjectParam.F.cpp_overload_set.type = name_ref F, imports.%ExplicitObjectParam.F.cpp_overload_set.value [concrete = constants.%ExplicitObjectParam.F.cpp_overload_set.value]
 // CHECK:STDOUT:   %bound_method.loc8: <bound method> = bound_method %e.ref, %F.ref.loc8
 // CHECK:STDOUT:   %.loc8: ref %ExplicitObjectParam = value_as_ref %e.ref
 // CHECK:STDOUT:   %addr.loc8: %ptr.7f5 = addr_of %.loc8
@@ -540,13 +540,13 @@ fn Call(e: Cpp.ExplicitObjectParam, n: i32, a: Cpp.Another) {
 // CHECK:STDOUT:   %n.ref: %i32 = name_ref n, %n
 // CHECK:STDOUT:   %Cpp.ref.loc9: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %ExplicitObjectParam.ref.loc9: type = name_ref ExplicitObjectParam, imports.%ExplicitObjectParam.decl [concrete = constants.%ExplicitObjectParam]
-// CHECK:STDOUT:   %F.ref.loc9: %.3e2 = name_ref F, imports.%.037 [concrete = constants.%.037]
+// CHECK:STDOUT:   %F.ref.loc9: %ExplicitObjectParam.F.cpp_overload_set.type = name_ref F, imports.%ExplicitObjectParam.F.cpp_overload_set.value [concrete = constants.%ExplicitObjectParam.F.cpp_overload_set.value]
 // CHECK:STDOUT:   %bound_method.loc9: <bound method> = bound_method %n.ref, %F.ref.loc9
 // CHECK:STDOUT:   %ExplicitObjectParam.F.call: init %empty_tuple.type = call imports.%ExplicitObjectParam.F.decl.28f5af.2(%n.ref)
 // CHECK:STDOUT:   %a.ref: %Another = name_ref a, %a
 // CHECK:STDOUT:   %Cpp.ref.loc10: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %ExplicitObjectParam.ref.loc10: type = name_ref ExplicitObjectParam, imports.%ExplicitObjectParam.decl [concrete = constants.%ExplicitObjectParam]
-// CHECK:STDOUT:   %F.ref.loc10: %.3e2 = name_ref F, imports.%.037 [concrete = constants.%.037]
+// CHECK:STDOUT:   %F.ref.loc10: %ExplicitObjectParam.F.cpp_overload_set.type = name_ref F, imports.%ExplicitObjectParam.F.cpp_overload_set.value [concrete = constants.%ExplicitObjectParam.F.cpp_overload_set.value]
 // CHECK:STDOUT:   %bound_method.loc10: <bound method> = bound_method %a.ref, %F.ref.loc10
 // CHECK:STDOUT:   %.loc10: ref %Another = value_as_ref %a.ref
 // CHECK:STDOUT:   %addr.loc10: %ptr.289 = addr_of %.loc10
@@ -318,8 +318,8 @@ fn MyF(bar: Cpp.Bar*);
 // CHECK:STDOUT: constants {
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
 // CHECK:STDOUT:   %Bar: type = class_type @Bar [concrete]
-// CHECK:STDOUT:   %.c07: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.617: %.c07 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %Bar.foo.cpp_overload_set.type: type = cpp_overload_set_type @Bar.foo.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %Bar.foo.cpp_overload_set.value: %Bar.foo.cpp_overload_set.type = cpp_overload_set_value @Bar.foo.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %Bar.foo.type: type = fn_type @Bar.foo [concrete]
 // CHECK:STDOUT:   %Bar.foo: %Bar.foo.type = struct_value () [concrete]
 // CHECK:STDOUT: }
@@ -330,7 +330,7 @@ fn MyF(bar: Cpp.Bar*);
 // CHECK:STDOUT:     import Cpp//...
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %Bar.decl: type = class_decl @Bar [concrete = constants.%Bar] {} {}
-// CHECK:STDOUT:   %.617: %.c07 = cpp_overload_set_value @<null name> [concrete = constants.%.617]
+// CHECK:STDOUT:   %Bar.foo.cpp_overload_set.value: %Bar.foo.cpp_overload_set.type = cpp_overload_set_value @Bar.foo.cpp_overload_set [concrete = constants.%Bar.foo.cpp_overload_set.value]
 // CHECK:STDOUT:   %Bar.foo.decl: %Bar.foo.type = fn_decl @Bar.foo [concrete = constants.%Bar.foo] {} {}
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -338,7 +338,7 @@ fn MyF(bar: Cpp.Bar*);
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %Bar.ref: type = name_ref Bar, imports.%Bar.decl [concrete = constants.%Bar]
-// CHECK:STDOUT:   %foo.ref: %.c07 = name_ref foo, imports.%.617 [concrete = constants.%.617]
+// CHECK:STDOUT:   %foo.ref: %Bar.foo.cpp_overload_set.type = name_ref foo, imports.%Bar.foo.cpp_overload_set.value [concrete = constants.%Bar.foo.cpp_overload_set.value]
 // CHECK:STDOUT:   %Bar.foo.call: init %empty_tuple.type = call imports.%Bar.foo.decl()
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
@@ -475,8 +475,8 @@ fn MyF(bar: Cpp.Bar*);
 // CHECK:STDOUT:   %MyF.type: type = fn_type @MyF [concrete]
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
 // CHECK:STDOUT:   %MyF: %MyF.type = struct_value () [concrete]
-// CHECK:STDOUT:   %.2e2: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.6e0: %.2e2 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %Bar.f.cpp_overload_set.type: type = cpp_overload_set_type @Bar.f.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %Bar.f.cpp_overload_set.value: %Bar.f.cpp_overload_set.type = cpp_overload_set_value @Bar.f.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %Bar.f.type: type = fn_type @Bar.f [concrete]
 // CHECK:STDOUT:   %Bar.f: %Bar.f.type = struct_value () [concrete]
 // CHECK:STDOUT: }
@@ -487,7 +487,7 @@ fn MyF(bar: Cpp.Bar*);
 // CHECK:STDOUT:     import Cpp//...
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %Bar.decl: type = class_decl @Bar [concrete = constants.%Bar] {} {}
-// CHECK:STDOUT:   %.6e0: %.2e2 = cpp_overload_set_value @<null name> [concrete = constants.%.6e0]
+// CHECK:STDOUT:   %Bar.f.cpp_overload_set.value: %Bar.f.cpp_overload_set.type = cpp_overload_set_value @Bar.f.cpp_overload_set [concrete = constants.%Bar.f.cpp_overload_set.value]
 // CHECK:STDOUT:   %Bar.f.decl: %Bar.f.type = fn_decl @Bar.f [concrete = constants.%Bar.f] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
@@ -514,7 +514,7 @@ fn MyF(bar: Cpp.Bar*);
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %bar.ref: %ptr.f68 = name_ref bar, %bar
 // CHECK:STDOUT:   %.loc8: ref %Bar = deref %bar.ref
-// CHECK:STDOUT:   %f.ref: %.2e2 = name_ref f, imports.%.6e0 [concrete = constants.%.6e0]
+// CHECK:STDOUT:   %f.ref: %Bar.f.cpp_overload_set.type = name_ref f, imports.%Bar.f.cpp_overload_set.value [concrete = constants.%Bar.f.cpp_overload_set.value]
 // CHECK:STDOUT:   %bound_method: <bound method> = bound_method %.loc8, %f.ref
 // CHECK:STDOUT:   %addr: %ptr.f68 = addr_of %.loc8
 // CHECK:STDOUT:   %Bar.f.call: init %empty_tuple.type = call imports.%Bar.f.decl(%addr)
@@ -90,8 +90,8 @@ var y: Cpp.Xint.r#type = 0;
 // CHECK:STDOUT:   %i32: type = class_type @Int, @Int(%int_32) [concrete]
 // CHECK:STDOUT:   %Base: type = class_type @Base [concrete]
 // CHECK:STDOUT:   %A.elem.c3f: type = unbound_element_type %A.0bedf0.1, %i32 [concrete]
-// CHECK:STDOUT:   %.658: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.d46: %.658 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %A.f.cpp_overload_set.type: type = cpp_overload_set_type @A.f.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %A.f.cpp_overload_set.value: %A.f.cpp_overload_set.type = cpp_overload_set_value @A.f.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %const.16f: type = const_type %A.0bedf0.1 [concrete]
 // CHECK:STDOUT:   %ptr.703: type = ptr_type %const.16f [concrete]
 // CHECK:STDOUT:   %f__carbon_thunk.type: type = fn_type @f__carbon_thunk [concrete]
@@ -122,7 +122,7 @@ var y: Cpp.Xint.r#type = 0;
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: imports {
-// CHECK:STDOUT:   %.d46: %.658 = cpp_overload_set_value @<null name> [concrete = constants.%.d46]
+// CHECK:STDOUT:   %A.f.cpp_overload_set.value: %A.f.cpp_overload_set.type = cpp_overload_set_value @A.f.cpp_overload_set [concrete = constants.%A.f.cpp_overload_set.value]
 // CHECK:STDOUT:   %f__carbon_thunk.decl: %f__carbon_thunk.type = fn_decl @f__carbon_thunk [concrete = constants.%f__carbon_thunk] {
 // CHECK:STDOUT:     <elided>
 // CHECK:STDOUT:   } {
@@ -137,7 +137,7 @@ var y: Cpp.Xint.r#type = 0;
 // CHECK:STDOUT: fn @F(%x.param: %A.0bedf0.1) -> %i32 {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %x.ref.loc9: %A.0bedf0.1 = name_ref x, %x
-// CHECK:STDOUT:   %f.ref: %.658 = name_ref f, imports.%.d46 [concrete = constants.%.d46]
+// CHECK:STDOUT:   %f.ref: %A.f.cpp_overload_set.type = name_ref f, imports.%A.f.cpp_overload_set.value [concrete = constants.%A.f.cpp_overload_set.value]
 // CHECK:STDOUT:   %bound_method.loc9: <bound method> = bound_method %x.ref.loc9, %f.ref
 // CHECK:STDOUT:   %.loc9_3: ref %A.0bedf0.1 = value_as_ref %x.ref.loc9
 // CHECK:STDOUT:   %addr: %ptr.270828.1 = addr_of %.loc9_3
@@ -289,8 +289,8 @@ fn MyF(bar: Cpp.Bar*);
 // CHECK:STDOUT: constants {
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
 // CHECK:STDOUT:   %Bar: type = class_type @Bar [concrete]
-// CHECK:STDOUT:   %.c07: type = cpp_overload_set_type @<null name> [concrete]
-// CHECK:STDOUT:   %.617: %.c07 = cpp_overload_set_value @<null name> [concrete]
+// CHECK:STDOUT:   %Bar.foo.cpp_overload_set.type: type = cpp_overload_set_type @Bar.foo.cpp_overload_set [concrete]
+// CHECK:STDOUT:   %Bar.foo.cpp_overload_set.value: %Bar.foo.cpp_overload_set.type = cpp_overload_set_value @Bar.foo.cpp_overload_set [concrete]
 // CHECK:STDOUT:   %Bar.foo.type: type = fn_type @Bar.foo [concrete]
 // CHECK:STDOUT:   %Bar.foo: %Bar.foo.type = struct_value () [concrete]
 // CHECK:STDOUT: }
@@ -301,7 +301,7 @@ fn MyF(bar: Cpp.Bar*);
 // CHECK:STDOUT:     import Cpp//...
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %Bar.decl: type = class_decl @Bar [concrete = constants.%Bar] {} {}
-// CHECK:STDOUT:   %.617: %.c07 = cpp_overload_set_value @<null name> [concrete = constants.%.617]
+// CHECK:STDOUT:   %Bar.foo.cpp_overload_set.value: %Bar.foo.cpp_overload_set.type = cpp_overload_set_value @Bar.foo.cpp_overload_set [concrete = constants.%Bar.foo.cpp_overload_set.value]
 // CHECK:STDOUT:   %Bar.foo.decl: %Bar.foo.type = fn_decl @Bar.foo [concrete = constants.%Bar.foo] {} {}
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -309,7 +309,7 @@ fn MyF(bar: Cpp.Bar*);
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %Bar.ref: type = name_ref Bar, imports.%Bar.decl [concrete = constants.%Bar]
-// CHECK:STDOUT:   %foo.ref: %.c07 = name_ref foo, imports.%.617 [concrete = constants.%.617]
+// CHECK:STDOUT:   %foo.ref: %Bar.foo.cpp_overload_set.type = name_ref foo, imports.%Bar.foo.cpp_overload_set.value [concrete = constants.%Bar.foo.cpp_overload_set.value]
 // CHECK:STDOUT:   %Bar.foo.call: init %empty_tuple.type = call imports.%Bar.foo.decl()
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }