test rename overhaul: step 8 - language tests

tests/language/src/StringUnicode4NegativeTest.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 StringUnicode4NegativeTest {
-
-  static testMain() {
-    // Unicode escapes must refer to valid Unicode points and not surrogate characters
-    String str = "Foo\u{FFFFFF}";
-    str = "Foo\uD800";
-    str = "Foo\uDC00";
-  }
-}
-
-main() {
-  StringUnicode4NegativeTest.testMain();
-}