Added support for exports and re-exports.

tests/language/export_cyclic_helper2.dart

Index: tests/language/export_cyclic_helper2.dart
diff --git a/tests/language/field_type_check2_test.dart b/tests/language/export_cyclic_helper2.dart
similarity index 52%
copy from tests/language/field_type_check2_test.dart
copy to tests/language/export_cyclic_helper2.dart
index 80925f4f7d4d307073a8c4634a9bd1b90c2e0c41..c602467089b656eb2e068657e3e1bdaa47c90d2f 100644
--- a/tests/language/field_type_check2_test.dart
+++ b/tests/language/export_cyclic_helper2.dart
@@ -2,19 +2,16 @@
 // 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.
 
-class A {
-  A a;
+library export_cyclic_helper2;
 
-  bar(c) {
-    c.a = 2; /// 01: dynamic type error
-  }
-}
+import 'export_cyclic_test.dart';
+import 'export_cyclic_helper3.dart';
+export 'export_cyclic_test.dart';
+export 'export_cyclic_helper3.dart';
 
-class B {
-  int a;
-}
-
-main() {
-  new A().bar(new A()); /// 01: continued
-  new A().bar(new B());
+class C {
+  A a;
+  B b;
+  C c;
+  D d;
 }