test rename overhaul: step 8 - language tests

tests/language/duplicate_implements_test.dart

 // 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.
 // Check that duplicate types in implements/extends list are
 // compile-time errors.
 
 interface I { }
 interface J { }
 interface K<T> { }
 
 class X implements I, J, I { }               /// 01: compile-time error
 class X implements J, I, K<int>, K<int> { }  /// 02: compile-time error
 
 interface Z extends I, J, J { }              /// 03: compile-time error
 interface Z extends K<int>, K<int> { }       /// 04: compile-time error
 
 main() {
   return null;
 }