Test scripts: Fix a missing Path.toNativePath() in reading status files for tests.

tools/testing/dart/test_suite.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.
 
 /**
  * Classes and methods for enumerating and preparing tests.
  *
  * This library includes:
  *
  * - Creating tests by listing all the Dart files in certain directories,
@@ skipping 311 matching lines @@
       // [forDirectory] adds name_dart2js.status for all tests suites, use it if
       // it exists, but otherwise skip it and don't fail.
       if (statusFilePath.endsWith('_dart2js.status')) {
         File file = new File.fromPath(dartDir.append(statusFilePath));
         if (!file.existsSync()) {
           filesRead++;
           continue;
         }
       }
       ReadTestExpectationsInto(testExpectations,
-                               dartDir.append(statusFilePath).toString(),
+                               dartDir.append(statusFilePath).toNativePath(),
                                configuration,
                                statusFileRead);
     }
   }
 
   void processDirectory() {
     Directory dir = new Directory.fromPath(suiteDir);
     dir.exists().then((exists) {
       if (!exists) {
         print('Directory containing tests not found: $suiteDir');
@@ skipping 980 matching lines @@
  * $noCrash tests are expected to be flaky but not crash
  * $pass tests are expected to pass
  * $failOk tests are expected to fail that we won't fix
  * $fail tests are expected to fail that we should fix
  * $crash tests are expected to crash that we should fix
  * $timeout tests are allowed to timeout
 """;
     print(report);
    }
 }