Use a dictionary-mode code cache on the map rather than a dual system.

include/v8.h

 // Copyright 2012 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.
 
 /** \mainpage V8 API Reference Guide
  *
  * V8 is Google's open source JavaScript engine.
  *
  * This set of documents provides reference material generated from the
  * V8 header file, include/v8.h.
@@ skipping 7335 matching lines @@
   static const int kNodeClassIdOffset = 1 * kApiPointerSize;
   static const int kNodeFlagsOffset = 1 * kApiPointerSize + 3;
   static const int kNodeStateMask = 0x7;
   static const int kNodeStateIsWeakValue = 2;
   static const int kNodeStateIsPendingValue = 3;
   static const int kNodeStateIsNearDeathValue = 4;
   static const int kNodeIsIndependentShift = 3;
   static const int kNodeIsPartiallyDependentShift = 4;
   static const int kNodeIsActiveShift = 4;
 
-  static const int kJSObjectType = 0xb8;
+  static const int kJSObjectType = 0xb6;
   static const int kFirstNonstringType = 0x80;
   static const int kOddballType = 0x83;
   static const int kForeignType = 0x87;
 
   static const int kUndefinedOddballKind = 5;
   static const int kNullOddballKind = 3;
 
   static const uint32_t kNumIsolateDataSlots = 4;
 
   V8_EXPORT static void CheckInitializedImpl(v8::Isolate* isolate);
@@ skipping 1382 matching lines @@
  */
 
 
 }  // namespace v8
 
 
 #undef TYPE_CHECK
 
 
 #endif  // INCLUDE_V8_H_