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

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

Index: sdk/lib/_internal/pub_generated/test/list_package_dirs/pubspec_error_test.dart
diff --git a/sdk/lib/_internal/pub/test/list_package_dirs/pubspec_error_test.dart b/sdk/lib/_internal/pub_generated/test/list_package_dirs/pubspec_error_test.dart
similarity index 62%
copy from sdk/lib/_internal/pub/test/list_package_dirs/pubspec_error_test.dart
copy to sdk/lib/_internal/pub_generated/test/list_package_dirs/pubspec_error_test.dart
index 6e4a4ee4b16e6433d4d84fb0e06f0b756e094191..5610e81a988dd259e37ca931b1b1b0a8e322e037 100644
--- a/sdk/lib/_internal/pub/test/list_package_dirs/pubspec_error_test.dart
+++ b/sdk/lib/_internal/pub_generated/test/list_package_dirs/pubspec_error_test.dart
@@ -13,15 +13,11 @@ import '../test_pub.dart';
 main() {
   initConfig();
   integration("reports the pubspec path when there is an error in it", () {
-    d.dir(appPath, [
-      d.file("pubspec.yaml", "some bad yaml")
-    ]).create();
+    d.dir(appPath, [d.file("pubspec.yaml", "some bad yaml")]).create();
 
-    schedulePub(args: ["list-package-dirs", "--format=json"],
-        outputJson: {
-          "error": contains('Error on line 1'),
-          "path": canonicalize(path.join(sandboxDir, appPath, "pubspec.yaml"))
-        },
-        exitCode: exit_codes.DATA);
+    schedulePub(args: ["list-package-dirs", "--format=json"], outputJson: {
+      "error": contains('Error on line 1'),
+      "path": canonicalize(path.join(sandboxDir, appPath, "pubspec.yaml"))
+    }, exitCode: exit_codes.DATA);
   });
-}
+}