Get binstubs working on Windows.

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

 import 'package:scheduled_test/scheduled_test.dart';
 import '../../descriptor.dart' as d;
 import '../../test_pub.dart';
+import 'utils.dart';
 main() {
   initConfig();
   integration("only creates binstubs for the listed executables", () {
     d.dir("foo", [d.pubspec({
         "name": "foo",
         "executables": {
           "one": "script",
           "two": "script",
           "three": "script"
         }
@@ skipping 10 matching lines @@
             "one",
             "--executable",
             "three"],
         output: contains("Installed executables one and three."));
     d.dir(
         cachePath,
         [
             d.dir(
                 "bin",
                 [
-                    d.matcherFile("one", contains("pub global run foo:script")),
-                    d.nothing("two"),
-                    d.matcherFile("three", contains("pub global run foo:script"))])]).validate();
+                    d.matcherFile(binStubName("one"), contains("pub global run foo:script")),
+                    d.nothing(binStubName("two")),
+                    d.matcherFile(
+                        binStubName("three"),
+                        contains("pub global run foo:script"))])]).validate();
   });
 }