Dart tests: Create generated tests in build directory in test.dart.

tools/testing/dart/test_suite.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.
 
 #library("test_suite");
 
 #import("status_file_parser.dart");
 #import("test_runner.dart");
 #import("multitest.dart");
 
@@ skipping 204 matching lines @@
                             args,
                             timeout,
                             completeHandler,
                             expectations,
                             isNegative));
       }
     }
 
 
     if (optionsFromFile['isMultitest']) {
-      DoMultitest(filename, createTestCase);
+      DoMultitest(filename,
+                  TestUtils.buildDir(configuration),
+                  directoryPath,
+                  createTestCase);
     } else {
       createTestCase(filename, optionsFromFile['isNegative']);
     }
   }
 
   void completeHandler(TestCase testCase) {
   }
 
 
   List<List<String>> argumentListsFromFile(String filename,
@@ skipping 127 matching lines @@
       args.add("--enable_leg");
     }
     if (configuration["component"] == "dartc") {
       if (configuration["mode"] == "release") {
         args.add("--optimize");
       }
     }
     return args;
   }
 }