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

sdk/lib/_internal/pub_generated/test/build/preserves_htaccess_test.dart

+// Copyright (c) 2013, 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 '../descriptor.dart' as d;
+import '../test_pub.dart';
+
+main() {
+  initConfig();
+
+  integration("preserves .htaccess as a special case", () {
+    d.dir(
+        appPath,
+        [
+            d.appPubspec(),
+            d.dir(
+                'web',
+                [d.file('.htaccess', 'fblthp'), d.file('.hidden', 'asdfgh')])]).create();
+
+    schedulePub(
+        args: ["build"],
+        output: new RegExp(r'Built \d+ files? to "build".'));
+
+    d.dir(
+        appPath,
+        [
+            d.dir(
+                'build',
+                [
+                    d.dir(
+                        'web',
+                        [d.file('.htaccess', 'fblthp'), d.nothing('.hidden')])])]).validate();
+  });
+}