Improve GVN handling of ElementTransitions.

src/objects.cc

 // 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 5487 matching lines @@
     int this_hash = MapsHashHelper(maps_, code_flags_);
     int other_hash = MapsHashHelper(&other_maps, other_flags);
     if (this_hash != other_hash) return false;
 
     // Full comparison: for each map in maps_, look for an equivalent map in
     // other_maps. This implementation is slow, but probably good enough for
     // now because the lists are short (<= 4 elements currently).
     for (int i = 0; i < maps_->length(); ++i) {
       bool match_found = false;
       for (int j = 0; j < other_maps.length(); ++j) {
-        if (maps_->at(i)->EquivalentTo(*other_maps.at(j))) {
+        if (*(maps_->at(i)) == *(other_maps.at(j))) {
           match_found = true;
           break;
         }
       }
       if (!match_found) return false;
     }
     return true;
   }
 
   static uint32_t MapsHashHelper(MapHandleList* maps, int code_flags) {
@@ skipping 7508 matching lines @@
   if (break_point_objects()->IsUndefined()) return 0;
   // Single break point.
   if (!break_point_objects()->IsFixedArray()) return 1;
   // Multiple break points.
   return FixedArray::cast(break_point_objects())->length();
 }
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 
 } }  // namespace v8::internal