Store the async-await compiled pub code directly in the repo.

sdk/lib/_internal/pub_generated/test/global/run/nonexistent_script_test.dart

Index: sdk/lib/_internal/pub_generated/test/global/run/nonexistent_script_test.dart
diff --git a/sdk/lib/_internal/pub/test/global/run/nonexistent_script_test.dart b/sdk/lib/_internal/pub_generated/test/global/run/nonexistent_script_test.dart
similarity index 69%
copy from sdk/lib/_internal/pub/test/global/run/nonexistent_script_test.dart
copy to sdk/lib/_internal/pub_generated/test/global/run/nonexistent_script_test.dart
index d69c65ab5861d40fb8a962499cedc929cba05ff9..85f15a82ca57149d246ebaa09de6239e0993fe82 100644
--- a/sdk/lib/_internal/pub/test/global/run/nonexistent_script_test.dart
+++ b/sdk/lib/_internal/pub_generated/test/global/run/nonexistent_script_test.dart
@@ -1,19 +1,11 @@
-// 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:path/path.dart' as p;
-
 import '../../../lib/src/exit_codes.dart' as exit_codes;
 import '../../test_pub.dart';
-
 main() {
   initConfig();
   integration('errors if the script does not exist.', () {
     servePackages((builder) => builder.serve("foo", "1.0.0"));
-
     schedulePub(args: ["global", "activate", "foo"]);
-
     var pub = pubRun(global: true, args: ["foo:script"]);
     pub.stderr.expect("Could not find ${p.join("bin", "script.dart")}.");
     pub.shouldExit(exit_codes.NO_INPUT);