test rename overhaul: step 8 - language tests

tests/language/string_concat_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.
 // String concatenation test.
 
 interface V {
   static final Version = "7.3.5.3";
 }
 
 
@@ skipping 50 matching lines @@
     Expect.equals(true, fake === "Milli Vanilli");
     Expect.equals(true, fake === "Milli " + 'Vanilli');
 
     Expect.equals(nofExceptions, 1);
   }
 }
 
 main() {
   StringConcatTest.testMain();
 }