sdk files reorganization to make dart2js a proper package

sdk/lib/_internal/compiler/js_lib/preambles/jsshell.js

-// Copyright (c) 2015, 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 = os.getenv("PWD");
-
-  // Global properties. "self" refers to the global object, so adding a
-  // property to "self" defines a global variable.
-  self.self = self;
-
-  self.location = { href: "file://" + workingDirectory + "/" };
-
-   function computeCurrentScript() {
-    try {
-      throw new Error();
-    } catch(e) {
-      var stack = e.stack;
-      print(stack);
-      // The jsshell stack looks like:
-      //   computeCurrentScript@...preambles/jsshell.js:23:13
-      //   self.document.currentScript@...preambles/jsshell.js:53:37
-      //   @/tmp/foo.js:308:1
-      //   @/tmp/foo.js:303:1
-      //   @/tmp/foo.js:5:1
-      var re = new RegExp("^.*@(.*):[0-9]*:[0-9]*$", "mg");
-      var lastMatch = null;
-      do {
-        var match = re.exec(stack);
-        if (match != null) lastMatch = match;
-      } while (match != null);
-      return lastMatch[1];
-    }
-  }
-
-  // Adding a 'document' is dangerous since it invalidates the 'typeof document'
-  // test to see if we are running in the browser. It means that the runtime
-  // needs to do more precise checks.
-  // Note that we can't run "currentScript" right away, since that would give
-  // us the location of the preamble file. Instead we wait for the first access
-  // which should happen just before invoking main. At this point we are in
-  // the main file and setting the currentScript property is correct.
-  // Note that we cannot use `thisFileName()`, since that would give us the
-  // preamble and not the script file.
-  var cachedCurrentScript = null;
-  self.document = { get currentScript() {
-      if (cachedCurrentScript == null) {
-        cachedCurrentScript = {src: computeCurrentScript()};
-      }
-      return cachedCurrentScript;
-    }
-  };
-
-  // Support for deferred loading.
-  self.dartDeferredLibraryLoader = function(uri, successCallback, errorCallback) {
-    try {
-      load(uri);
-      successCallback();
-    } catch (error) {
-      errorCallback(error);
-    }
-  };
-})(this)
-
-var getKeys = function(obj){
-   var keys = [];
-   for(var key in obj){
-      keys.push(key);
-   }
-   return keys;
-}