test rename overhaul: step 8 - language tests

tests/language/src/Issue4157508Test.dart

-// Copyright (c) 2011, 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 Issue4157508Test {
-  Issue4157508Test(var v) {
-    var d = new Date.fromEpoch(v, const TimeZone.utc());
-  }
-
-  static void testMain() {
-    var d = new Issue4157508Test(0);
-  }
-}
-
-main() {
-  Issue4157508Test.testMain();
-}