Fix Harmony Maps and WeakMaps for undefined values.

src/objects.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 3304 matching lines @@
 
 // ObjectHashTable maps keys that are arbitrary objects to object values by
 // using the identity hash of the key for hashing purposes.
 class ObjectHashTable: public HashTable<ObjectHashTableShape<2>, Object*> {
  public:
   static inline ObjectHashTable* cast(Object* obj) {
     ASSERT(obj->IsHashTable());
     return reinterpret_cast<ObjectHashTable*>(obj);
   }
 
-  // Looks up the value associated with the given key. The undefined value is
+  // Looks up the value associated with the given key. The hole value is
   // returned in case the key is not present.
   Object* Lookup(Object* key);
 
   // Adds (or overwrites) the value associated with the given key. Mapping a
-  // key to the undefined value causes removal of the whole entry.
+  // key to the hole value causes removal of the whole entry.
   MUST_USE_RESULT MaybeObject* Put(Object* key, Object* value);
 
  private:
   friend class MarkCompactCollector;
 
   void AddEntry(int entry, Object* key, Object* value);
   void RemoveEntry(int entry);
 
   // Returns the index to the value of an entry.
   static inline int EntryToValueIndex(int entry) {
@@ skipping 5452 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_