Improve load IC so it can call a native accessor even if the holder is

src/objects.h

Index: src/objects.h
===================================================================
--- src/objects.h	(revision 12254)
+++ src/objects.h	(working copy)
@@ -4684,7 +4684,8 @@
 
   class IsShared:              public BitField<bool, 0, 1> {};
   class FunctionWithPrototype: public BitField<bool, 1, 1> {};
-  class LastAddedBits:         public BitField<int, 2, 11> {};
+  class DictionaryMap:         public BitField<bool, 2, 1> {};
+  class LastAddedBits:         public BitField<int, 3, 11> {};
 
   // Tells whether the object in the prototype property will be used
   // for instances created from this function.  If the prototype
@@ -4830,6 +4831,13 @@
   inline void set_is_shared(bool value);
   inline bool is_shared();
 
+  // Tells whether the map is used for JSObjects in dictionary mode (ie
+  // normalized objects, ie objects for which HasFastProperties returns false).
+  // A map can never be used for both dictionary mode and fast mode JSObjects.
+  // False by default and for HeapObjects that are not JSObjects.
+  inline void set_dictionary_map(bool value);
+  inline bool is_dictionary_map();
+
   // Tells whether the instance needs security checks when accessing its
   // properties.
   inline void set_is_access_check_needed(bool access_check_needed);
@@ -5150,6 +5158,7 @@
   // Bit positions for bit field 3
   static const int kIsShared = 0;
   static const int kFunctionWithPrototype = 1;
+  static const int kDictionaryMap = 2;
 
   typedef FixedBodyDescriptor<kPointerFieldsBeginOffset,
                               kPointerFieldsEndOffset,