[turbofan] Make FieldAccess::name usable in practice.

src/compiler/js-native-context-specialization.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/js-native-context-specialization.h"
 
 #include "src/accessors.h"
 #include "src/code-factory.h"
 #include "src/compilation-dependencies.h"
 #include "src/compiler/access-builder.h"
@@ skipping 235 matching lines @@
       if (access_mode == AccessMode::kLoad &&
           access_info.holder().ToHandle(&holder)) {
         this_receiver = jsgraph()->Constant(holder);
       }
       Node* this_storage = this_receiver;
       if (!field_index.is_inobject()) {
         this_storage = this_effect = graph()->NewNode(
             simplified()->LoadField(AccessBuilder::ForJSObjectProperties()),
             this_storage, this_effect, this_control);
       }
-      FieldAccess field_access = {kTaggedBase, field_index.offset(), name,
+      const char* field_name =
+          AccessBuilder::GetNameForTracing(name, graph()->zone());
+      FieldAccess field_access = {kTaggedBase, field_index.offset(), field_name,
                                   field_type, MachineType::AnyTagged()};
       if (access_mode == AccessMode::kLoad) {
         if (field_type->Is(Type::UntaggedFloat64())) {
           if (!field_index.is_inobject() || field_index.is_hidden_field() ||
               !FLAG_unbox_double_fields) {
             this_storage = this_effect =
                 graph()->NewNode(simplified()->LoadField(field_access),
                                  this_storage, this_effect, this_control);
             field_access.offset = HeapNumber::kValueOffset;
-            field_access.name = MaybeHandle<Name>();
+            field_access.name = "HeapNumber::value";
           }
           field_access.machine_type = MachineType::Float64();
         }
         this_value = this_effect =
             graph()->NewNode(simplified()->LoadField(field_access),
                              this_storage, this_effect, this_control);
       } else {
         DCHECK_EQ(AccessMode::kStore, access_mode);
         if (field_type->Is(Type::UntaggedFloat64())) {
           Node* check =
@@ skipping 24 matching lines @@
                   this_box, this_value, this_effect, this_control);
               this_value = this_box;
 
               field_access.type = Type::TaggedPointer();
             } else {
               // We just store directly to the MutableHeapNumber.
               this_storage = this_effect =
                   graph()->NewNode(simplified()->LoadField(field_access),
                                    this_storage, this_effect, this_control);
               field_access.offset = HeapNumber::kValueOffset;
-              field_access.name = MaybeHandle<Name>();
+              field_access.name = "HeapNumber::value";
               field_access.machine_type = MachineType::Float64();
             }
           } else {
             // Unboxed double field, we store directly to the field.
             field_access.machine_type = MachineType::Float64();
           }
         } else if (field_type->Is(Type::TaggedSigned())) {
           Node* check =
               graph()->NewNode(simplified()->ObjectIsSmi(), this_value);
           Node* branch = graph()->NewNode(common()->Branch(BranchHint::kTrue),
@@ skipping 698 matching lines @@
 }
 
 
 SimplifiedOperatorBuilder* JSNativeContextSpecialization::simplified() const {
   return jsgraph()->simplified();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8