Add mirrors tests

test/codegen/lib/mirrors/deferred_type_other.dart

Index: test/codegen/lib/mirrors/deferred_type_other.dart
diff --git a/test/codegen/language/regress_22443_lib.dart b/test/codegen/lib/mirrors/deferred_type_other.dart
similarity index 81%
copy from test/codegen/language/regress_22443_lib.dart
copy to test/codegen/lib/mirrors/deferred_type_other.dart
index 4499cf98bf813857987c8d5574b10047577b87d2..87dfd47ab5fb12c68691dc59e4d31855407a1dcd 100644
--- a/test/codegen/language/regress_22443_lib.dart
+++ b/test/codegen/lib/mirrors/deferred_type_other.dart
@@ -2,7 +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 regress_22443;
+library deferred_type_other;
 
-class LazyClass {
-}
+class DeferredType {}