Don't hide interceptors in mirrors.

tests/lib/mirrors/runtime_type_test.dart

Index: tests/lib/mirrors/runtime_type_test.dart
diff --git a/tests/compiler/dart2js_extra/closure_type_reflection2_test.dart b/tests/lib/mirrors/runtime_type_test.dart
similarity index 56%
copy from tests/compiler/dart2js_extra/closure_type_reflection2_test.dart
copy to tests/lib/mirrors/runtime_type_test.dart
index ef97222c9cf6f7a9174e9611cec9e8470f93b247..fd446d32b0b8db6da48163ebc0020d62f4c831db 100644
--- a/tests/compiler/dart2js_extra/closure_type_reflection2_test.dart
+++ b/tests/lib/mirrors/runtime_type_test.dart
@@ -2,21 +2,19 @@
 // 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 classes referenced from a signature of a tear-off closure
-// are emitted.
+library test.runtime_type_test;
 
-@MirrorsUsed(targets: 'C')
+@MirrorsUsed(targets: 'test.runtime_type_test', override: '*')
 import 'dart:mirrors';
 
 import 'package:expect/expect.dart';
 
 class A {}
 
-class C {
-  A foo() {}
+class B {
+  get runtimeType => A;
 }
 
 main() {
-  Expect.isFalse(reflect(new C().foo).function.returnType.toString()
-      .contains('dynamic'));
+  Expect.equals(reflect(new B()).type, reflectClass(B));
 }