Reland regexp global optimizations.

test/mjsunit/regexp-global.js

 // Copyright 2012 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 221 matching lines @@
 
   // Test 1b: String.replace with function.
   function f() { return "x"; }
   test_replace(test_1_expectation, subject, /a1/g, f);
 
   // Test 2a: String.replace with empty string.
   test_replace(test_2_expectation, subject, /a1/g, "");
 
   // Test 3a: String.match.
   test_match(test_3_expectation, subject, /a1/g);
-}
+}
+
+
+// Test String hashing (compiling regular expression includes hashing).
+var crosscheck = "\x80";
+for (var i = 0; i < 12; i++) crosscheck += crosscheck;
+new RegExp(crosscheck);
+
+var subject = "ascii~only~string~here~";
+var replacement = "\x80";
+var result = subject.replace(/~/g, replacement);
+for (var i = 0; i < 5; i++) result += result;
+new RegExp(result);