Migrate test block 5 to Dart 2.0.

tests/corelib/date_time2_test.dart

Index: tests/corelib/date_time2_test.dart
diff --git a/tests/corelib/date_time2_test.dart b/tests/corelib/date_time2_test.dart
deleted file mode 100644
index 6a0bb87dae5258b3149232f6f1b6ec29f06e4a3f..0000000000000000000000000000000000000000
--- a/tests/corelib/date_time2_test.dart
+++ /dev/null
@@ -1,16 +0,0 @@
-// Copyright (c) 2012, 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";
-
-// Dart test program for DateTime's hashCode.
-
-main() {
-  var d = DateTime.parse("2000-01-01T00:00:00Z");
-  var d2 = DateTime.parse("2000-01-01T00:00:01Z");
-  // There is no guarantee that the hashcode for these two dates is different,
-  // but in the worst case we will have to fix this test.
-  // The important test here is, that DateTime .
-  Expect.isFalse(d.hashCode == d2.hashCode);
-}