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

test/mjsunit/regress/regress-1129.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 24 matching lines @@
 var r = RegExp(source);
 try {
   // Try to compile in UC16 mode, and drop the exception.
   r.test("\x80");
   assertUnreachable();
 } catch (e) {
 }
 
 // Trigger a heap validation.
 gc();