cleans up sdk patching so we no longer have unresolved names

tool/input_sdk_patch/preambles/jsshell.js

-// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-// Javascript preamble, that lets the output of dart2js run on JSShell.
-
-(function(self) {
-  // Using strict mode to avoid accidentally defining global variables.
-  "use strict"; // Should be first statement of this function.
-
-  // Location (Uri.base)
-
-  var workingDirectory = environment["PWD"];
-  self.location = { href: "file://" + workingDirectory + "/" };
-
-  // Global properties. "self" refers to the global object, so adding a
-  // property to "self" defines a global variable.
-  self.self = self;
-})(this)