Fixed dartc test/build setup, so test can run on Windows. Might be related to dart:2623

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 1166 matching lines @@
          '$buildDir/analyzer/dart_analyzer_tests.jar',
          // Third party libraries.
          '$dartDir/third_party/args4j/2.0.12/args4j-2.0.12.jar',
          '$dartDir/third_party/guava/r09/guava-r09.jar',
          '$dartDir/third_party/rhino/1_7R3/js.jar',
          '$dartDir/third_party/hamcrest/v1_3/hamcrest-core-1.3.0RC2.jar',
          '$dartDir/third_party/hamcrest/v1_3/hamcrest-generator-1.3.0RC2.jar',
          '$dartDir/third_party/hamcrest/v1_3/hamcrest-integration-1.3.0RC2.jar',
          '$dartDir/third_party/hamcrest/v1_3/hamcrest-library-1.3.0RC2.jar',
          '$dartDir/third_party/junit/v4_8_2/junit.jar'],
-        ':');  // Path separator.
+        Platform.operatingSystem == 'windows'? ';': ':');  // Path separator.
   }
 }
 
 
 class TestUtils {
   /**
    * Creates a directory using a [relativePath] to an existing
    * [base] directory if that [relativePath] does not already exist.
    */
   static Directory mkdirRecursive(Path base, Path relativePath) {
@@ skipping 209 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);
    }
 }