test rename overhaul: step 8 - language tests

tests/language/switch4_negative_test.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.
 // Discover unresolved case labels.
 
 class Switch4NegativeTest {
 
   static testMain() {
     var a = 5;
     var x;
     switch (a) {
       case 1: x = 1; continue L; // unresolved forward reference
       case 6: x = 2; break;
       case 8:  break;
     }
     return a;
   }
 }
 
 main() {
   Switch4NegativeTest.testMain();
 }