test rename overhaul: step 3 _tests.dart => _test.dart

utils/tests/string_encoding/unicode_test.dart

 #!/usr/bin/env 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.
 
 #library("unicode_tests");
 #import("dunit.dart");
 #import("../../../lib/utf/utf.dart");
 
 void main() {
@@ skipping 27 matching lines @@
   }
 
   void testEmptyCodepointsToString() {
     Expect.stringEquals("", codepointsToString(<int>[]));
   }
 
   void testEmptyStringToCodepoints() {
     Expect.listEquals([], stringToCodepoints(""));
   }
 }