Add @MirrorsUsed annotations to speed up tests.

tests/lib/mirrors/equality_test.dart

Index: tests/lib/mirrors/equality_test.dart
diff --git a/tests/lib/mirrors/equality_test.dart b/tests/lib/mirrors/equality_test.dart
index 8b627b0edcefe1a593b4073cbea853cb0187a5ac..4bab8ff9fb10c684aeaa5874dee41628c17e5bc2 100644
--- a/tests/lib/mirrors/equality_test.dart
+++ b/tests/lib/mirrors/equality_test.dart
@@ -2,15 +2,9 @@
 // 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.
 
-// This tests uses the multi-test "ok" feature:
-// none: Trimmed behaviour. Passing on the VM.
-// 01: Trimmed version for dart2js.
-// 02: Full version passing in the VM.
-//
-// TODO(rmacnak,ahe): Remove multi-test when VM and dart2js are on par.
-
 library test.class_equality_test;
 
+@MirrorsUsed(targets: "test.class_equality_test")
 import 'dart:mirrors';
 
 import 'package:expect/expect.dart';