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

sdk/lib/_internal/pub_generated/test/list_package_dirs/lockfile_error_test.dart

Index: sdk/lib/_internal/pub_generated/test/list_package_dirs/lockfile_error_test.dart
diff --git a/sdk/lib/_internal/pub/test/list_package_dirs/lockfile_error_test.dart b/sdk/lib/_internal/pub_generated/test/list_package_dirs/lockfile_error_test.dart
similarity index 59%
copy from sdk/lib/_internal/pub/test/list_package_dirs/lockfile_error_test.dart
copy to sdk/lib/_internal/pub_generated/test/list_package_dirs/lockfile_error_test.dart
index 893e20679480d004117789c1c26b7635d2844754..d9b872a7c5ffe83f6e1fa33e2bacd08935090f94 100644
--- a/sdk/lib/_internal/pub/test/list_package_dirs/lockfile_error_test.dart
+++ b/sdk/lib/_internal/pub_generated/test/list_package_dirs/lockfile_error_test.dart
@@ -13,16 +13,13 @@ import '../test_pub.dart';
 main() {
   initConfig();
   integration("reports the lockfile path when there is an error in it", () {
-    d.dir(appPath, [
-      d.appPubspec(),
-      d.file("pubspec.lock", "some bad yaml")
-    ]).create();
+    d.dir(
+        appPath,
+        [d.appPubspec(), d.file("pubspec.lock", "some bad yaml")]).create();
 
-    schedulePub(args: ["list-package-dirs", "--format=json"],
-        outputJson: {
-          "error": contains('The lockfile must be a YAML mapping.'),
-          "path": canonicalize(path.join(sandboxDir, appPath, "pubspec.lock"))
-        },
-        exitCode: exit_codes.DATA);
+    schedulePub(args: ["list-package-dirs", "--format=json"], outputJson: {
+      "error": contains('The lockfile must be a YAML mapping.'),
+      "path": canonicalize(path.join(sandboxDir, appPath, "pubspec.lock"))
+    }, exitCode: exit_codes.DATA);
   });
-}
+}