The order of evaluation in parseInt is wrong.

src/v8natives.js

 // Copyright 2011 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 88 matching lines @@
     // vs 800ns).  The following optimization makes parseInt on a
     // non-Smi number 9 times faster (230ns vs 2070ns).  Together
     // they make parseInt on a string 1.4% slower (274ns vs 270ns).
     if (%_IsSmi(string)) return string;
     if (IS_NUMBER(string) &&
         ((0.01 < string && string < 1e9) ||
             (-1e9 < string && string < -0.01))) {
       // Truncate number.
       return string | 0;
     }
+    string = TO_STRING_INLINE(string);
     radix = radix | 0;
   } else {
+    // The spec says ToString should be evaluated before ToInt32.
+    string = TO_STRING_INLINE(string);
     radix = TO_INT32(radix);
     if (!(radix == 0 || (2 <= radix && radix <= 36)))
       return $NaN;
   }
-  string = TO_STRING_INLINE(string);
+
   if (%_HasCachedArrayIndex(string) &&
       (radix == 0 || radix == 10)) {
     return %_GetCachedArrayIndex(string);
   }
   return %StringParseInt(string, radix);
 }
 
 
 // ECMA-262 - 15.1.2.3
 function GlobalParseFloat(string) {
@@ skipping 1397 matching lines @@
 // ----------------------------------------------------------------------------
 
 function SetupFunction() {
   InstallFunctions($Function.prototype, DONT_ENUM, $Array(
     "bind", FunctionBind,
     "toString", FunctionToString
   ));
 }
 
 SetupFunction();