Revert "Revert "Use native async/await support in pub.""

sdk/lib/_internal/pub_generated/test/global/binstubs/creates_executables_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';
-
-main() {
-  initConfig();
-  integration("creates binstubs for each executable in the pubspec", () {
-    servePackages((builder) {
-      builder.serve("foo", "1.0.0", pubspec: {
-        "executables": {
-          "one": null,
-          "two-renamed": "second"
-        }
-      },
-          contents: [
-              d.dir(
-                  "bin",
-                  [
-                      d.file("one.dart", "main(args) => print('one');"),
-                      d.file("second.dart", "main(args) => print('two');"),
-                      d.file("nope.dart", "main(args) => print('nope');")])]);
-    });
-
-    schedulePub(
-        args: ["global", "activate", "foo"],
-        output: contains("Installed executables one and two-renamed."));
-
-    d.dir(
-        cachePath,
-        [
-            d.dir(
-                "bin",
-                [
-                    d.matcherFile(binStubName("one"), contains("one")),
-                    d.matcherFile(binStubName("two-renamed"), contains("second")),
-                    d.nothing(binStubName("two")),
-                    d.nothing(binStubName("nope"))])]).validate();
-  });
-}