Get binstubs working on Windows.

sdk/lib/_internal/pub_generated/test/global/binstubs/binstub_runs_global_run_if_no_snapshot_test.dart

 import 'package:scheduled_test/scheduled_test.dart';
 import '../../descriptor.dart' as d;
 import '../../test_pub.dart';
+import 'utils.dart';
 main() {
   initConfig();
   integration("the binstubs runs pub global run if there is no snapshot", () {
     d.dir("foo", [d.pubspec({
         "name": "foo",
         "executables": {
           "foo-script": "script"
         }
       }),
           d.dir("bin", [d.file("script.dart", "main() => print('ok');")])]).create();
     schedulePub(
         args: ["global", "activate", "--source", "path", "../foo"],
         output: contains("Installed executable foo-script."));
     d.dir(
         cachePath,
         [
             d.dir(
                 "bin",
                 [
                     d.matcherFile(
-                        "foo-script",
+                        binStubName("foo-script"),
                         contains("pub global run foo:script"))])]).validate();
   });
 }