Migrate test block 5 to Dart 2.0.

tests/corelib/date_time_parse_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 "package:expect/expect.dart";
-
-check(DateTime expected, String str) {
-  DateTime actual = DateTime.parse(str);
-  Expect.equals(expected, actual); // Only checks if they are at the same time.
-  Expect.equals(expected.isUtc, actual.isUtc);
-}
-
-bool get supportsMicroseconds =>
-    new DateTime.fromMicrosecondsSinceEpoch(1).microsecondsSinceEpoch == 1;
-
-main() {
-  check(new DateTime(2012, 02, 27, 13, 27), "2012-02-27 13:27:00");
-  if (supportsMicroseconds) {
-    check(new DateTime.utc(2012, 02, 27, 13, 27, 0, 123, 456),
-        "2012-02-27 13:27:00.123456z");
-  } else {
-    check(new DateTime.utc(2012, 02, 27, 13, 27, 0, 123, 456),
-        "2012-02-27 13:27:00.123z");
-  }
-  check(new DateTime(2012, 02, 27, 13, 27), "20120227 13:27:00");
-  check(new DateTime(2012, 02, 27, 13, 27), "20120227T132700");
-  check(new DateTime(2012, 02, 27), "20120227");
-  check(new DateTime(2012, 02, 27), "+20120227");
-  check(new DateTime.utc(2012, 02, 27, 14), "2012-02-27T14Z");
-  check(new DateTime.utc(-12345, 1, 1), "-123450101 00:00:00 Z");
-  check(new DateTime.utc(2012, 02, 27, 14), "2012-02-27T14+00");
-  check(new DateTime.utc(2012, 02, 27, 14), "2012-02-27T14+0000");
-  check(new DateTime.utc(2012, 02, 27, 14), "2012-02-27T14+00:00");
-  check(new DateTime.utc(2012, 02, 27, 14), "2012-02-27T14 +00:00");
-
-  check(new DateTime.utc(2015, 02, 14, 13, 0, 0, 0), "2015-02-15T00:00+11");
-  check(new DateTime.utc(2015, 02, 14, 13, 0, 0, 0), "2015-02-15T00:00:00+11");
-  check(
-      new DateTime.utc(2015, 02, 14, 13, 0, 0, 0), "2015-02-15T00:00:00+11:00");
-
-  if (supportsMicroseconds) {
-    check(new DateTime.utc(2015, 02, 15, 0, 0, 0, 500, 500),
-        "2015-02-15T00:00:00.500500Z");
-    check(new DateTime.utc(2015, 02, 15, 0, 0, 0, 511, 500),
-        "2015-02-15T00:00:00.511500Z");
-  } else {
-    check(new DateTime.utc(2015, 02, 15, 0, 0, 0, 501),
-        "2015-02-15T00:00:00.501Z");
-    check(new DateTime.utc(2015, 02, 15, 0, 0, 0, 512),
-        "2015-02-15T00:00:00.512Z");
-  }
-}