Added support for exports and re-exports.

tests/language/export_helper3.dart

Index: tests/language/export_helper3.dart
diff --git a/tests/language/issue1363_lib.dart b/tests/language/export_helper3.dart
similarity index 64%
copy from tests/language/issue1363_lib.dart
copy to tests/language/export_helper3.dart
index 0dc03eab54c26efd4d7fcd6e4b6e2faca05b4883..c4cf3d824978b03fa4176142940d5a6098ac1917 100644
--- a/tests/language/issue1363_lib.dart
+++ b/tests/language/export_helper3.dart
@@ -2,13 +2,11 @@
 // 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.
 
-#library('Issue1363');
+library export_helper3;
 
-class C { }
+import 'export_helper4.dart';
+export 'export_helper4.dart';
 
-class Cup<T> {
-  var foo;
-  Cup(this.foo);
+class Exported extends ReExported {
 
-  T getContents() => foo;
-}
+}