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

utils/tests/string_encoding/utf16_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("utf16_tests");
 #import("dunit.dart");
 #import("../../string_encoding/unicode_core.dart");
 #import("../../string_encoding/utf16.dart");
 
@@ skipping 116 matching lines @@
     // specify types
     Expect.equals(44032, (new List<int>
         .from(decodeUtf16beAsIterable(testKoreanCharSubsetUtf16beBom)))[0]);
     Expect.equals(44032, (new List<int>
         .from(decodeUtf16leAsIterable(testKoreanCharSubsetUtf16le)))[0]);
     Expect.equals(UNICODE_BOM, (new List<int>
         .from(decodeUtf16beAsIterable(testKoreanCharSubsetUtf16beBom,
               stripBom: false)))[0]);
   }
 }