Preliminary checked mirrors (not ready for review yet)

pkg/checked_mirrors/test/from_sdk/library_metatarget_test.dart

Index: pkg/checked_mirrors/test/from_sdk/library_metatarget_test.dart
diff --git a/tests/lib/mirrors/library_metatarget_test.dart b/pkg/checked_mirrors/test/from_sdk/library_metatarget_test.dart
similarity index 89%
copy from tests/lib/mirrors/library_metatarget_test.dart
copy to pkg/checked_mirrors/test/from_sdk/library_metatarget_test.dart
index 8bbb64ff03c4dd320b444f92512963e983a243ff..ae9f11922d9e797197244a3337be3dbe4b607b03 100644
--- a/tests/lib/mirrors/library_metatarget_test.dart
+++ b/pkg/checked_mirrors/test/from_sdk/library_metatarget_test.dart
@@ -10,7 +10,7 @@ import 'library_metatarget_test_lib.dart';
 import 'library_metatarget_test_annotations_lib.dart';
 
 @MirrorsUsed(metaTargets:const [Reflectable])
-import 'dart:mirrors';
+import 'package:checked_mirrors/checked_mirrors.dart';
 
 void main() {
   print(new A());