Add mirrors tests

test/codegen/lib/mirrors/typedef_library.dart

Index: test/codegen/lib/mirrors/typedef_library.dart
diff --git a/test/codegen/language/empty_library.dart b/test/codegen/lib/mirrors/typedef_library.dart
similarity index 88%
copy from test/codegen/language/empty_library.dart
copy to test/codegen/lib/mirrors/typedef_library.dart
index fe101dc999a80b771ab0decabb137ef8c509623c..fcb3231612c0219e91e8b17b9983f6576c20f351 100644
--- a/test/codegen/language/empty_library.dart
+++ b/test/codegen/lib/mirrors/typedef_library.dart
@@ -2,4 +2,6 @@
 // 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 empty_library;
+library bar;
+
+typedef G();