Added back helper file accidentally deleted during test block 219 migration.

tests/lib/mirrors/delegate_function_invocation_test.dart

-// Copyright (c) 2014, 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.
-
-library test.delegate_function_invocation;
-
-@MirrorsUsed(targets: "test.delegate_function_invocation")
-import 'dart:mirrors';
-
-import 'package:expect/expect.dart';
-
-class Proxy {
-  var targetMirror;
-  Proxy(target) : this.targetMirror = reflect(target);
-  noSuchMethod(invocation) => targetMirror.delegate(invocation);
-}
-
-testClosure() {
-  var proxy = new Proxy(() => 42);
-  Expect.equals(42, proxy());
-  Expect.equals(42, proxy.call());
-}
-
-class FakeFunction {
-  call() => 43;
-}
-
-testFakeFunction() {
-  var proxy = new Proxy(new FakeFunction());
-  Expect.equals(43, proxy());
-  Expect.equals(43, proxy.call());
-}
-
-topLevelFunction() => 44;
-
-testTopLevelTearOff() {
-  var proxy = new Proxy(topLevelFunction);
-  Expect.equals(44, proxy());
-  Expect.equals(44, proxy.call());
-}
-
-class C {
-  method() => 45;
-}
-
-testInstanceTearOff() {
-  var proxy = new Proxy(new C().method);
-  Expect.equals(45, proxy());
-  Expect.equals(45, proxy.call());
-}
-
-main() {
-  testClosure();
-  testFakeFunction();
-  testTopLevelTearOff();
-  testInstanceTearOff();
-}