Capture register clearing on loop iteration

test/cctest/test-regexp.cc

 // Copyright 2008 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 1530 matching lines @@
     } else {
       CHECK(!InClass(i, included));
       CHECK(!InClass(i, excluded));
     }
   }
 }
 
 
 TEST(Graph) {
   V8::Initialize(NULL);
-  Execute("(?:a|)*", false, true, true);
+  Execute("(?:(a)+)?", false, true, true);
 }