[Isolates] Merge 7051:7083 from bleeding_edge to isolates.

test/mjsunit/regress/regress-1237.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 16 matching lines @@
 
 // Deoptimization after a conditional expression in an effect context should
 // not see the value of the expression.
 function observe(x, y) { return x; }
 function test(x) {
   return observe(1, ((x? observe(observe.prototype.x): 'c'), x + 1));
 }
 
 for (var i = 0; i < 10000000; ++i) test(0);
 test("a");