Start pulling pub from its own repo.

sdk/lib/_internal/pub/test/global/binstubs/explicit_and_no_executables_options_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 '../../../lib/src/exit_codes.dart' as exit_codes;
-import '../../descriptor.dart' as d;
-import '../../test_pub.dart';
-
-main() {
-  initConfig();
-  integration("errors if -x and --no-executables are both passed", () {
-    d.dir("foo", [
-      d.libPubspec("foo", "1.0.0")
-    ]).create();
-
-    schedulePub(args: [
-      "global", "activate", "--source", "path", "../foo",
-      "-x", "anything", "--no-executables"
-    ], error: contains("Cannot pass both --no-executables and --executable."),
-        exitCode: exit_codes.USAGE);
-  });
-}