ES6 symbols: Allow symbols as property names

src/property.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 30 matching lines @@
 // property index (in the actual instance-descriptor array) and
 // optionally a piece of data.
 //
 
 class Descriptor BASE_EMBEDDED {
  public:
   static int IndexFromValue(Object* value) {
     return Smi::cast(value)->value();
   }
 
-  MUST_USE_RESULT MaybeObject* KeyToInternalizedString() {
-    if (!StringShape(key_).IsInternalized()) {
-      MaybeObject* maybe_result = HEAP->InternalizeString(key_);
+  MUST_USE_RESULT MaybeObject* KeyToUniqueName() {
+    if (!key_->IsUniqueName()) {
+      MaybeObject* maybe_result = HEAP->InternalizeString(String::cast(key_));
       if (!maybe_result->To(&key_)) return maybe_result;
     }
     return key_;
   }
 
-  String* GetKey() { return key_; }
+  Name* GetKey() { return key_; }
   Object* GetValue() { return value_; }
   PropertyDetails GetDetails() { return details_; }
 
 #ifdef OBJECT_PRINT
   void Print(FILE* out);
 #endif
 
   void SetEnumerationIndex(int index) {
     details_ = PropertyDetails(details_.attributes(), details_.type(), index);
   }
 
   void SetSortedKeyIndex(int index) { details_ = details_.set_pointer(index); }
 
  private:
-  String* key_;
+  Name* key_;
   Object* value_;
   PropertyDetails details_;
 
  protected:
   Descriptor() : details_(Smi::FromInt(0)) {}
 
-  void Init(String* key, Object* value, PropertyDetails details) {
+  void Init(Name* key, Object* value, PropertyDetails details) {
     key_ = key;
     value_ = value;
     details_ = details;
   }
 
-  Descriptor(String* key, Object* value, PropertyDetails details)
+  Descriptor(Name* key, Object* value, PropertyDetails details)
       : key_(key),
         value_(value),
         details_(details) { }
 
-  Descriptor(String* key,
+  Descriptor(Name* key,
              Object* value,
              PropertyAttributes attributes,
              PropertyType type,
              int index)
       : key_(key),
         value_(value),
         details_(attributes, type, index) { }
 
   friend class DescriptorArray;
 };
 
 
 class FieldDescriptor: public Descriptor {
  public:
-  FieldDescriptor(String* key,
+  FieldDescriptor(Name* key,
                   int field_index,
                   PropertyAttributes attributes,
                   int index = 0)
       : Descriptor(key, Smi::FromInt(field_index), attributes, FIELD, index) {}
 };
 
 
 class ConstantFunctionDescriptor: public Descriptor {
  public:
-  ConstantFunctionDescriptor(String* key,
+  ConstantFunctionDescriptor(Name* key,
                              JSFunction* function,
                              PropertyAttributes attributes,
                              int index)
       : Descriptor(key, function, attributes, CONSTANT_FUNCTION, index) {}
 };
 
 
 class CallbacksDescriptor:  public Descriptor {
  public:
-  CallbacksDescriptor(String* key,
+  CallbacksDescriptor(Name* key,
                       Object* foreign,
                       PropertyAttributes attributes,
                       int index = 0)
       : Descriptor(key, foreign, attributes, CALLBACKS, index) {}
 };
 
 
 // Holds a property index value distinguishing if it is a field index or an
 // index inside the object header.
 class PropertyIndex {
@@ skipping 335 matching lines @@
   JSReceiver* holder_;
   int number_;
   bool cacheable_;
   PropertyDetails details_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_PROPERTY_H_