Migrate test block 1 to Dart 2.0.

tests/corelib/apply4_test.dart

-// Copyright (c) 2015, 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 "package:expect/expect.dart";
-
-// Testing Function.apply calls work correctly for arities that are not
-// otherwise present in the program (and thus might not have stubs
-// generated).
-
-class A {
-  foo(x, [y, z, a, b, c, d = 99, e, f, g, h, i, j]) => "$x $d";
-}
-
-main() {
-  var a = new A();
-  var clos = a.foo;
-  Expect.equals(Function.apply(clos, ["well"]), "well 99");
-  Expect.equals(Function.apply(clos, ["well", 0, 2, 4, 3, 6, 9, 10]), "well 9");
-}