Add first version of runAsync.

runtime/lib/event_loop_patch.dart

 // Copyright (c) 2013, 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.
 
-// Imported by deferred_class_test.dart.
-
-library deferred_class_library;
-
-class MyClass {
-  foo(x) {
-    print('MyClass.foo($x)');
-    return (x - 3) ~/ 2;
+patch class _AsyncRun {
+  /* patch */ static void _enqueueImmediate(void callback()) {
+    // TODO(floitsch): don't use the Timer to enqueue the immediate callback.
+    Timer.run(callback);
   }
 }