Backport hash collision workaround to 3.6.

test/mjsunit/debug-evaluate-locals-optimized-double.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 32 matching lines @@
 
       for (var i = 0; i < exec_state.frameCount(); i++) {
         var frame = exec_state.frame(i);
         if (i < exec_state.frameCount() - 1) {
           var expected_a = i * 2 + 1 + (i * 2 + 1) / 100;
           var expected_b = i * 2 + 2 + (i * 2 + 2) / 100;
           var expected_x = (i + 1) * 2 + 1 + ((i + 1) * 2 + 1) / 100;
           var expected_y = (i + 1) * 2 + 2 + ((i + 1) * 2 + 2) / 100;
 
           // All frames except the bottom one has normal variables a and b.
-          assertEquals('a', frame.localName(0));
-          assertEquals('b', frame.localName(1));
-          assertEquals(expected_a, frame.localValue(0).value());
-          assertEquals(expected_b, frame.localValue(1).value());
+          var a = ('a' === frame.localName(0)) ? 0 : 1;
+          var b = 1 - a;
+          assertEquals('a', frame.localName(a));
+          assertEquals('b', frame.localName(b));
+          assertEquals(expected_a, frame.localValue(a).value());
+          assertEquals(expected_b, frame.localValue(b).value());
 
           // All frames except the bottom one has arguments variables x and y.
           assertEquals('x', frame.argumentName(0));
           assertEquals('y', frame.argumentName(1));
           assertEquals(expected_x, frame.argumentValue(0).value());
           assertEquals(expected_y, frame.argumentValue(1).value());
 
           // All frames except the bottom one have two scopes.
           assertEquals(2, frame.scopeCount());
           assertEquals(debug.ScopeType.Local, frame.scope(0).scopeType());
@@ skipping 107 matching lines @@
 // Test calling f normally and as a constructor.
 f(11.11, 12.12);
 testingConstructCall = true;
 new f(11.11, 12.12);
 
 // Make sure that the debug event listener vas invoked.
 assertFalse(exception, "exception in listener " + exception)
 assertTrue(listenerComplete);
 
 Debug.setListener(null);