Merge 6168:6800 from bleeding_edge to experimental/gc branch.

test/mjsunit/regress/regress-crbug-72736.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 17 matching lines @@
 // See http://crbug.com/72736
 
 // This tests that Object.defineProperty actually allows to change the value of
 // a non-writable property if configurable is true.
 
 var obj = {};
 Object.defineProperty(obj, 'foo', { value: 10, configurable: true });
 assertEquals(obj.foo, 10);
 Object.defineProperty(obj, 'foo', { value: 20, configurable: true });
 assertEquals(obj.foo, 20);