Fix bug 1137. No longer allow the RegExp /(*)/.

test/mjsunit/regexp.js

 // 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 658 matching lines @@
 // Only partially anchored.
 var re = /(?:a|bc$)/;
 assertTrue(re.test("a"));
 assertTrue(re.test("bc"));
 assertEquals(["a"], re.exec("abc"));
 assertEquals(4, re.exec("zimzamzumba").index);
 assertEquals(["bc"], re.exec("zimzomzumbc"));
 assertFalse(re.test("c"));
 assertFalse(re.test(""));
 
+// Valid syntax in ES5.
+re = RegExp("(?:x)*");
+re = RegExp("(x)*");
+
+// Syntax extension relative to ES5, for matching JSC (and ES3).
+// Shouldn't throw.
+re = RegExp("(?=x)*");
+re = RegExp("(?!x)*");
+
+// Should throw. Shouldn't hit asserts in debug mode.
+assertThrows("RegExp('(*)')");
+assertThrows("RegExp('(?:*)')");
+assertThrows("RegExp('(?=*)')");
+assertThrows("RegExp('(?!*)')");