Merge bleeding edge up to 8774 into the GC branch.

test/mjsunit/regress/regress-1560.js

 // Copyright 2011 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 48 matching lines @@
 for (var i = 0; i < 5; i++) write(mkArray(), 0);
 %OptimizeFunctionOnNextCall(write);
 write(mkCOWArray(), 0);
 var failure = mkCOWArray();
 
 // Cleanup, then polymorphic case.
 %DeoptimizeFunction(write);
 gc();
 test([mkArray, mkNumberDictionary], write);
 test([mkArray, mkNumberDictionary, mkCOWArray], write);