Migrated test block 218 to Dart 2.0.

tests/lib_strong/mirrors/closures_test.dart

-// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
-// 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.
-
-import 'dart:mirrors';
-import 'package:expect/expect.dart';
-import 'stringify.dart';
-
-testIntercepted() {
-  var instance = [];
-  var closureMirror = reflect(instance.toString);
-  var methodMirror = closureMirror.function;
-  Expect.equals(#toString, methodMirror.simpleName);
-  Expect.equals('[]', closureMirror.apply([]).reflectee);
-}
-
-testNonIntercepted() {
-  var closure = new Map().containsKey;
-  var closureMirror = reflect(closure);
-  var methodMirror = closureMirror.function;
-  Expect.equals(#containsKey, methodMirror.simpleName);
-  Expect.isFalse(closureMirror.apply([7]).reflectee);
-}
-
-main() {
-  testIntercepted();
-  testNonIntercepted();
-}