[ic] Load IC data handlers now support prototype chain checks with global and dictionary objects.

src/ic/x64/handler-compiler-x64.cc

 // Copyright 2014 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.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/ic/handler-compiler.h"
 
 #include "src/api-arguments.h"
 #include "src/field-type.h"
@@ skipping 457 matching lines @@
     // checks are allowed in stubs.
     DCHECK(current_map->IsJSGlobalProxyMap() ||
            !current_map->is_access_check_needed());
 
     prototype = handle(JSObject::cast(current_map->prototype()));
     if (current_map->IsJSGlobalObjectMap()) {
       GenerateCheckPropertyCell(masm(), Handle<JSGlobalObject>::cast(current),
                                 name, scratch2, miss);
     } else if (current_map->is_dictionary_map()) {
       DCHECK(!current_map->IsJSGlobalProxyMap());  // Proxy maps are fast.
-      if (!name->IsUniqueName()) {
-        DCHECK(name->IsString());
-        name = factory()->InternalizeString(Handle<String>::cast(name));
-      }
+      DCHECK(name->IsUniqueName());
       DCHECK(current.is_null() ||
              current->property_dictionary()->FindEntry(name) ==
                  NameDictionary::kNotFound);
 
       if (depth > 1) {
         Handle<WeakCell> weak_cell =
             Map::GetOrCreatePrototypeWeakCell(current, isolate());
         __ LoadWeakValue(reg, weak_cell, miss);
       }
       GenerateDictionaryNegativeLookup(masm(), miss, reg, name, scratch1,
@@ skipping 203 matching lines @@
   // Return the generated code.
   return GetCode(kind(), name);
 }
 
 
 #undef __
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64