Include entity name in FacetAccessType formatted name (#6339)

Format the entity name into the instruction name for a FacetAccessType
of a SymbolicBinding. This means (T as type) gets formatted as
`T.as_type` instead of just as `as_type` for the non-canonical
FacetAccessType instruction. The same is already true for the canonical
SymbolicBindingType.

toolchain/check/testdata/interface/fail_assoc_const_alias.carbon

@@ -237,7 +237,7 @@ interface C {
 // CHECK:STDOUT:     %return.patt: <error> = return_slot_pattern [concrete]
 // CHECK:STDOUT:     %return.param_patt: <error> = out_param_pattern %return.patt, call_param0 [concrete]
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %as_type: type = facet_access_type @J.%Self [symbolic = %Self.binding.as_type (constants.%Self.binding.as_type)]
+// CHECK:STDOUT:     %Self.as_type: type = facet_access_type @J.%Self [symbolic = %Self.binding.as_type (constants.%Self.binding.as_type)]
 // CHECK:STDOUT:     %U.ref: <error> = name_ref U, <error> [concrete = <error>]
 // CHECK:STDOUT:     %return.param: ref <error> = out_param call_param0
 // CHECK:STDOUT:     %return: ref <error> = return_slot %return.param
@@ -370,8 +370,8 @@ interface C {
 // CHECK:STDOUT:     %return.patt: @J2.F2.%pattern_type (%pattern_type.f94) = return_slot_pattern [concrete]
 // CHECK:STDOUT:     %return.param_patt: @J2.F2.%pattern_type (%pattern_type.f94) = out_param_pattern %return.patt, call_param0 [concrete]
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %as_type: type = facet_access_type @J2.%Self [symbolic = %Self.binding.as_type (constants.%Self.binding.as_type)]
-// CHECK:STDOUT:     %I2.facet.loc15_14.2: %I2.type = facet_value %as_type, (constants.%I2.lookup_impl_witness.1de) [symbolic = %I2.facet.loc15_14.1 (constants.%I2.facet)]
+// CHECK:STDOUT:     %Self.as_type: type = facet_access_type @J2.%Self [symbolic = %Self.binding.as_type (constants.%Self.binding.as_type)]
+// CHECK:STDOUT:     %I2.facet.loc15_14.2: %I2.type = facet_value %Self.as_type, (constants.%I2.lookup_impl_witness.1de) [symbolic = %I2.facet.loc15_14.1 (constants.%I2.facet)]
 // CHECK:STDOUT:     %.loc15: %I2.type = converted @J2.%Self, %I2.facet.loc15_14.2 [symbolic = %I2.facet.loc15_14.1 (constants.%I2.facet)]
 // CHECK:STDOUT:     %impl.elem0.loc15_14.2: type = impl_witness_access constants.%I2.lookup_impl_witness.1de, element0 [symbolic = %impl.elem0.loc15_14.1 (constants.%impl.elem0.804)]
 // CHECK:STDOUT:     %U2.ref: type = name_ref U2, %impl.elem0.loc15_14.2 [symbolic = %impl.elem0.loc15_14.1 (constants.%impl.elem0.804)]
@@ -518,7 +518,7 @@ interface C {
 // CHECK:STDOUT:     %return.patt: <error> = return_slot_pattern [concrete]
 // CHECK:STDOUT:     %return.param_patt: <error> = out_param_pattern %return.patt, call_param0 [concrete]
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %as_type: type = facet_access_type @B.%Self [symbolic = %Self.binding.as_type (constants.%Self.binding.as_type.322)]
+// CHECK:STDOUT:     %Self.as_type: type = facet_access_type @B.%Self [symbolic = %Self.binding.as_type (constants.%Self.binding.as_type.322)]
 // CHECK:STDOUT:     %F.ref: <error> = name_ref F, <error> [concrete = <error>]
 // CHECK:STDOUT:     %return.param: ref <error> = out_param call_param0
 // CHECK:STDOUT:     %return: ref <error> = return_slot %return.param

toolchain/check/testdata/named_constraint/empty_generic.carbon

@@ -182,10 +182,10 @@ fn G(T:! Z, U:! Empty(T), V:! type) {
 // CHECK:STDOUT:     %F.ref.loc23: %F.type = name_ref F, file.%F.decl [concrete = constants.%F]
 // CHECK:STDOUT:     %T.ref.loc23_5: %Z.type = name_ref T, %T.loc20_6.2 [symbolic = %T.loc20_6.1 (constants.%T.3b3)]
 // CHECK:STDOUT:     %T.ref.loc23_8: %Z.type = name_ref T, %T.loc20_6.2 [symbolic = %T.loc20_6.1 (constants.%T.3b3)]
-// CHECK:STDOUT:     %T.as_type.loc23: type = facet_access_type %T.ref.loc23_5 [symbolic = %T.binding.as_type (constants.%T.binding.as_type)]
-// CHECK:STDOUT:     %.loc23_9.1: type = converted %T.ref.loc23_5, %T.as_type.loc23 [symbolic = %T.binding.as_type (constants.%T.binding.as_type)]
-// CHECK:STDOUT:     %as_type.loc23: type = facet_access_type constants.%T.3b3 [symbolic = %T.binding.as_type (constants.%T.binding.as_type)]
-// CHECK:STDOUT:     %facet_value.loc23_9.1: %type = facet_value %as_type.loc23, () [symbolic = %facet_value.loc23_9.2 (constants.%facet_value.146)]
+// CHECK:STDOUT:     %T.as_type.loc23_9.1: type = facet_access_type %T.ref.loc23_5 [symbolic = %T.binding.as_type (constants.%T.binding.as_type)]
+// CHECK:STDOUT:     %.loc23_9.1: type = converted %T.ref.loc23_5, %T.as_type.loc23_9.1 [symbolic = %T.binding.as_type (constants.%T.binding.as_type)]
+// CHECK:STDOUT:     %T.as_type.loc23_9.2: type = facet_access_type constants.%T.3b3 [symbolic = %T.binding.as_type (constants.%T.binding.as_type)]
+// CHECK:STDOUT:     %facet_value.loc23_9.1: %type = facet_value %T.as_type.loc23_9.2, () [symbolic = %facet_value.loc23_9.2 (constants.%facet_value.146)]
 // CHECK:STDOUT:     %.loc23_9.2: %type = converted constants.%T.3b3, %facet_value.loc23_9.1 [symbolic = %facet_value.loc23_9.2 (constants.%facet_value.146)]
 // CHECK:STDOUT:     %F.specific_fn.loc23_3.1: <specific function> = specific_function %F.ref.loc23, @F(constants.%T.binding.as_type, constants.%facet_value.146) [symbolic = %F.specific_fn.loc23_3.2 (constants.%F.specific_fn.d3f)]
 // CHECK:STDOUT:     %F.call.loc23: init %empty_tuple.type = call %F.specific_fn.loc23_3.1()
@@ -194,8 +194,8 @@ fn G(T:! Z, U:! Empty(T), V:! type) {
 // CHECK:STDOUT:     %U.ref: @G.%type (%Empty.type.b8d23b.2) = name_ref U, %U.loc20_13.2 [symbolic = %U.loc20_13.1 (constants.%U.aa1546.2)]
 // CHECK:STDOUT:     %T.as_type.loc24: type = facet_access_type %T.ref.loc24 [symbolic = %T.binding.as_type (constants.%T.binding.as_type)]
 // CHECK:STDOUT:     %.loc24_9.1: type = converted %T.ref.loc24, %T.as_type.loc24 [symbolic = %T.binding.as_type (constants.%T.binding.as_type)]
-// CHECK:STDOUT:     %as_type.loc24: type = facet_access_type constants.%U.aa1546.2 [symbolic = %U.binding.as_type (constants.%U.binding.as_type)]
-// CHECK:STDOUT:     %facet_value.loc24_9.1: %type = facet_value %as_type.loc24, () [symbolic = %facet_value.loc24_9.2 (constants.%facet_value.356)]
+// CHECK:STDOUT:     %U.as_type: type = facet_access_type constants.%U.aa1546.2 [symbolic = %U.binding.as_type (constants.%U.binding.as_type)]
+// CHECK:STDOUT:     %facet_value.loc24_9.1: %type = facet_value %U.as_type, () [symbolic = %facet_value.loc24_9.2 (constants.%facet_value.356)]
 // CHECK:STDOUT:     %.loc24_9.2: %type = converted constants.%U.aa1546.2, %facet_value.loc24_9.1 [symbolic = %facet_value.loc24_9.2 (constants.%facet_value.356)]
 // CHECK:STDOUT:     %F.specific_fn.loc24_3.1: <specific function> = specific_function %F.ref.loc24, @F(constants.%T.binding.as_type, constants.%facet_value.356) [symbolic = %F.specific_fn.loc24_3.2 (constants.%F.specific_fn.df4)]
 // CHECK:STDOUT:     %F.call.loc24: init %empty_tuple.type = call %F.specific_fn.loc24_3.1()

toolchain/sem_ir/inst_namer.cpp

@@ -868,9 +868,16 @@ auto InstNamer::NamingContext::NameInst() -> void {
       return;
     }
     case CARBON_KIND(FacetAccessType inst): {
+      auto name_id = SemIR::NameId::None;
       if (auto name =
               sem_ir().insts().TryGetAs<NameRef>(inst.facet_value_inst_id)) {
-        AddInstNameId(name->name_id, ".as_type");
+        name_id = name->name_id;
+      } else if (auto bind = sem_ir().insts().TryGetAs<SymbolicBinding>(
+                     inst.facet_value_inst_id)) {
+        name_id = sem_ir().entity_names().Get(bind->entity_name_id).name_id;
+      }
+      if (name_id.has_value()) {
+        AddInstNameId(name_id, ".as_type");
       } else {
         AddInstName("as_type");
       }