Merge up to 8597 to experimental/gc from the bleeding edge.

test/mjsunit/regress/regress-1472.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 20 matching lines @@
 "xxx".match(r1);
 
 var r2 = /(?:a(?:b(?:c(?:d(?:e(?:f(?:g(?:h(?:i(?:j(?:k(?:l(?:FooBar){0,2}){0,2}){0,2}){0,2}){0,2}){0,2}){0,2}){0,2}){0,2}){0,2}){0,2}){0,2}){0,2}/;
 "xxx".match(r2);
 
 var r3 = /(?:a(?:b(?:c(?:d(?:e(?:f(?:g(?:h(?:i(?:j(?:k(?:l(?:FooBar){2}){2}){2}){2}){2}){2}){2}){2}){2}){2}){2}){2}){2}/;
 "xxx".match(r3);
 
 var r4 = /(?:a(?:b(?:c(?:d(?:e(?:f(?:g(?:h(?:i(?:FooBar){3,6}){3,6}){3,6}){3,6}){3,6}){3,6}){3,6}){3,6}){3,6}){3,6}/;
 "xxx".match(r4);