Added support for exports and re-exports.

tests/language/export_test.dart

Index: tests/language/export_test.dart
diff --git a/tests/compiler/dart2js_extra/regress/4562_test.dart b/tests/language/export_test.dart
similarity index 50%
copy from tests/compiler/dart2js_extra/regress/4562_test.dart
copy to tests/language/export_test.dart
index 13a30edc8c3407cf7ed64d28819af3d7d6149172..b5938d95c78f5bf90ff2a1f497bb17c66982ef7e 100644
--- a/tests/compiler/dart2js_extra/regress/4562_test.dart
+++ b/tests/language/export_test.dart
@@ -2,15 +2,17 @@
 // 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.
 
-void main() {
-  var foo = new Foo();
-  var bar = new Bar(); /// 01: compile-time error
-}
+// Test export and re-export.
 
-class Foo {
-  factory Foo() => null;
-}
+library export_test;
 
-class Bar extends Foo {
-  Bar(); /// 01: continued
+import 'export_helper1.dart';
+import 'export_helper3.dart' as lib;
+
+void main() {
+  print(new Exported());
+  print(new ReExported());
+  print(new lib.Exported());
+  print(new lib.ReExported());
 }
+