Get binstubs working on Windows.

sdk/lib/_internal/pub/test/global/binstubs/removes_even_if_not_in_pubspec_test.dart

 // Copyright (c) 2014, 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.
 
 import 'package:scheduled_test/scheduled_test.dart';
 
 import '../../descriptor.dart' as d;
 import '../../test_pub.dart';
+import 'utils.dart';
 
 main() {
   initConfig();
   integration("removes all binstubs for package", () {
     d.dir("foo", [
       d.pubspec({
         "name": "foo",
         "executables": {
           "foo": null
         }
@@ skipping 12 matching lines @@
         "name": "foo"
       })
     ]).create();
 
     // Deactivate.
     schedulePub(args: ["global", "deactivate", "foo"]);
 
     // It should still be deleted.
     d.dir(cachePath, [
       d.dir("bin", [
-        d.nothing("foo")
+        d.nothing(binStubName("foo"))
       ])
     ]).validate();
   });
 }