Wrap runtime.js in a function.

src/messages.js

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // -------------------------------------------------------------------
 
 var $errorToString;
 var $formatMessage;
 var $getStackTraceLine;
 var $messageGetPositionInLine;
@@ skipping 251 matching lines @@
 
 
 // When formatting internally created error messages, do not
 // invoke overwritten error toString methods but explicitly use
 // the error to string method. This is to avoid leaking error
 // objects between script tags in a browser setting.
 function ToStringCheckErrorObject(obj) {
   if (CanBeSafelyTreatedAsAnErrorObject(obj)) {
     return %_CallFunction(obj, ErrorToString);
   } else {
-    return ToString(obj);
+    return $toString(obj);
   }
 }
 
 
 function ToDetailString(obj) {
   if (obj != null && IS_OBJECT(obj) && obj.toString === $objectToString) {
     var constructor = obj.constructor;
     if (typeof constructor == "function") {
       var constructorName = constructor.name;
       if (IS_STRING(constructorName) && constructorName !== "") {
@@ skipping 799 matching lines @@
   %FunctionSetInstanceClassName(f, 'Error');
   %AddNamedProperty(f.prototype, 'constructor', f, DONT_ENUM);
   %AddNamedProperty(f.prototype, 'name', name, DONT_ENUM);
   %SetCode(f, function(m) {
     if (%_IsConstructCall()) {
       try { captureStackTrace(this, f); } catch (e) { }
       // Define all the expected properties directly on the error
       // object. This avoids going through getters and setters defined
       // on prototype objects.
       if (!IS_UNDEFINED(m)) {
-        %AddNamedProperty(this, 'message', ToString(m), DONT_ENUM);
+        %AddNamedProperty(this, 'message', $toString(m), DONT_ENUM);
       }
     } else {
       return new f(m);
     }
   });
   %SetNativeFlag(f);
   return f;
 };
 
 GlobalError = DefineError(function Error() { });
@@ skipping 132 matching lines @@
   return MakeGenericError(GlobalTypeError, type, [arg]);
 }
 
 //Boilerplate for exceptions for stack overflows. Used from
 //Isolate::StackOverflow().
 $stackOverflowBoilerplate = MakeRangeError(kStackOverflow);
 %DefineAccessorPropertyUnchecked($stackOverflowBoilerplate, 'stack',
                                  StackTraceGetter, StackTraceSetter, DONT_ENUM);
 
 })();