Add mirrors tests

test/codegen/lib/mirrors/mirrors_used_merge_test.dart

Index: test/codegen/lib/mirrors/mirrors_used_merge_test.dart
diff --git a/test/codegen/language/regress_13462_0_test.dart b/test/codegen/lib/mirrors/mirrors_used_merge_test.dart
similarity index 50%
copy from test/codegen/language/regress_13462_0_test.dart
copy to test/codegen/lib/mirrors/mirrors_used_merge_test.dart
index b87bf1f24d7378ea99edd41562464cc8f67ffed6..534c5e71dd2ad7bd495a54afa24d99001495c707 100644
--- a/test/codegen/language/regress_13462_0_test.dart
+++ b/test/codegen/lib/mirrors/mirrors_used_merge_test.dart
@@ -2,8 +2,14 @@
 // 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.
 
+/// Test that two MirrorsUsed annotations can be merged with out crashing
+/// dart2js.
+
+@MirrorsUsed(symbols: const ['foo'])
+@MirrorsUsed(symbols: const ['bar'])
 import 'dart:mirrors';
 
 main() {
-  print(MirrorSystem.getName(#foo));
+  // Do nothing, just make sure that merging the annotations doesn't crash
+  // dart2js.
 }