Don't record elements transition slots since it will contain a map.

src/transitions.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 51 matching lines @@
 
 
 static bool InsertionPointFound(String* key1, String* key2) {
   return key1->Hash() > key2->Hash();
 }
 
 
 MaybeObject* TransitionArray::NewWith(String* name, Map* target) {
   TransitionArray* result;
 
-  { MaybeObject* maybe_array;
-    maybe_array = TransitionArray::Allocate(1);
-    if (!maybe_array->To(&result)) return maybe_array;
-  }
+  MaybeObject* maybe_array;
+  maybe_array = TransitionArray::Allocate(1);

[Michael Starzinger, 2012/07/19 21:09:02]

Merge the above two lines into one.

+  if (!maybe_array->To(&result)) return maybe_array;
 
   FixedArray::WhitenessWitness witness(result);
 
   result->Set(0, name, target, witness);
   return result;
 }
 
 
 MaybeObject* TransitionArray::CopyInsert(String* name, Map* target) {
   TransitionArray* result;
@@ skipping 36 matching lines @@
 
   for (; insertion_index < number_of_transitions; ++insertion_index) {
     result->CopyFrom(this, insertion_index, insertion_index + 1, witness);
   }
 
   return result;
 }
 
 
 } }  // namespace v8::internal