Add support for //# sourceURL similar to deprecated //@ sourceURL one.

test/mjsunit/stack-traces.js

 // Copyright 2009 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 46 matching lines @@
 function testEval() {
   eval("function Doo() { FAIL; }; Doo();");
 }
 
 function testNestedEval() {
   var x = "FAIL";
   eval("function Outer() { eval('function Inner() { eval(x); }'); Inner(); }; Outer();");
 }
 
 function testEvalWithSourceURL() {
-  eval("function Doo() { FAIL; }; Doo();\n//@ sourceURL=res://name");
+  eval("function Doo() { FAIL; }; Doo();\n//# sourceURL=res://name");
 }
 
 function testNestedEvalWithSourceURL() {
   var x = "FAIL";
   var innerEval = 'function Inner() { eval(x); }\n//@ sourceURL=res://inner-eval';
-  eval("function Outer() { eval(innerEval); Inner(); }; Outer();\n//@ sourceURL=res://outer-eval");
+  eval("function Outer() { eval(innerEval); Inner(); }; Outer();\n//# sourceURL=res://outer-eval");
 }
 
 function testValue() {
   Number.prototype.causeError = function () { FAIL; };
   (1).causeError();
 }
 
 function testConstructor() {
   function Plonk() { FAIL; }
   new Plonk();
@@ skipping 236 matching lines @@
   message = e.message;
 }
 
 assertEquals("abc", message);
 
 // Test that modifying Error.prepareStackTrace by itself works.
 Error.prepareStackTrace = function() { Error.prepareStackTrace = "custom"; };
 new Error();
 
 assertEquals("custom", Error.prepareStackTrace);