Remake of the load elimination fix made earlier (r18884).

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 5971 matching lines @@
   inline void ClearTransitions(Heap* heap,
                                WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
 
   void DeprecateTransitionTree();
   void DeprecateTarget(Name* key, DescriptorArray* new_descriptors);
 
   Map* FindRootMap();
   Map* FindUpdatedMap(int verbatim, int length, DescriptorArray* descriptors);
   Map* FindLastMatchMap(int verbatim, int length, DescriptorArray* descriptors);
 
+  inline int GetInObjectPropertyOffset(int index);
+  // Calculates index of the in-object property by offset. Values below zero
+  // correspond to accesses to the object header fields.
+  inline int GetInObjectPropertyIndex(int offset);
+
   int NumberOfFields();
 
   bool InstancesNeedRewriting(Map* target,
                               int target_number_of_fields,
                               int target_inobject,
                               int target_unused);
   static Handle<Map> GeneralizeAllFieldRepresentations(
       Handle<Map> map,
       Representation new_representation);
   static Handle<Map> GeneralizeRepresentation(
@@ skipping 4765 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_