Migrating another batch of tests to dart 2.

tests/language_2/closures_initializer_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.
 
 class A<T> {
   var t;
   A() : t = (() => new List<T>());
 }
 
 class B<T> {
   var t;
   B() : t = (() => T);
 }
 
 expect(result, expected) {
   if (result != expected) {
     throw 'Expected $expected, got $result';
   }
 }
 
 main() {
   expect(new A<int>().t() is List<int>, true);
   expect(new A<String>().t() is List<int>, false);
   expect(new B<int>().t() is Type, true);
   expect(new B<int>().t(), int);
 }