fixes #221, initial sync*, async, async* implementation

test/codegen/language/async_backwards_compatibility_1_test.dart

Index: test/codegen/language/async_backwards_compatibility_1_test.dart
diff --git a/test/codegen/language/async_backwards_compatibility_1_test.dart b/test/codegen/language/async_backwards_compatibility_1_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..93908797af9400f0cdc751626158e1f4e39f6af5
--- /dev/null
+++ b/test/codegen/language/async_backwards_compatibility_1_test.dart
@@ -0,0 +1,18 @@
+// 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.
+
+import 'dart:async';
+import 'async_helper_lib.dart' as async;
+
+class A {
+  async.async get async => null;
+}
+
+async.async topLevel() => null;
+
+main() {
+  var a = new A();
+  var b = a.async;
+  var c = topLevel();
+}