Add mirrors tests

test/codegen/lib/mirrors/library_without_declaration.dart

Index: test/codegen/lib/mirrors/library_without_declaration.dart
diff --git a/test/codegen/language/enum_private_lib.dart b/test/codegen/lib/mirrors/library_without_declaration.dart
similarity index 76%
copy from test/codegen/language/enum_private_lib.dart
copy to test/codegen/lib/mirrors/library_without_declaration.dart
index c8fb00f6f3f757100cf1daa96a61ead3f92c0f8c..4f21997869c757a4c8d4ea284d228da6324aef21 100644
--- a/test/codegen/language/enum_private_lib.dart
+++ b/test/codegen/lib/mirrors/library_without_declaration.dart
@@ -2,9 +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 enum_private_lib;
+// NO LIBRARY DECLARATION
 
-enum Enum2 {
-  _A,
-  _B,
-}
+class ClassInLibraryWithoutDeclaration {}