Assume a method can be torn off, if it's accessible through reflection.

tests/lib/mirrors/get_field_test.dart

Index: tests/lib/mirrors/get_field_test.dart
diff --git a/tests/lib/mirrors/unmangled_type_test.dart b/tests/lib/mirrors/get_field_test.dart
similarity index 52%
copy from tests/lib/mirrors/unmangled_type_test.dart
copy to tests/lib/mirrors/get_field_test.dart
index dbc6b62437908677c6fb6c1dab670b8d0dd7d2b6..feaf18fed20dc1a106993ab8ee53caf4a4cfc776 100644
--- a/tests/lib/mirrors/unmangled_type_test.dart
+++ b/tests/lib/mirrors/get_field_test.dart
@@ -2,14 +2,18 @@
 // 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.
 
+@MirrorsUsed(targets: "A")
 import 'dart:mirrors';
 
 import 'package:expect/expect.dart';
 
-class Foo {
+class A {
+  foo(y, [x]) => y;
 }
 
 main() {
-  Expect.stringEquals('Foo', '${new Foo().runtimeType}');
-  Expect.stringEquals('foo', MirrorSystem.getName(new Symbol('foo')));
+  // We are using `getField` to tear off `foo`. We must make sure that all
+  // stub methods are installed.
+  var closure = reflect(new A()).getField(#foo).reflectee;
+  Expect.equals("b", closure("b"));
 }