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

sdk/lib/_internal/pub_generated/test/transformer/fails_to_load_a_pubspec_with_reserved_transformer_test.dart

Index: sdk/lib/_internal/pub_generated/test/transformer/fails_to_load_a_pubspec_with_reserved_transformer_test.dart
diff --git a/sdk/lib/_internal/pub/test/transformer/fails_to_load_a_pubspec_with_reserved_transformer_test.dart b/sdk/lib/_internal/pub_generated/test/transformer/fails_to_load_a_pubspec_with_reserved_transformer_test.dart
similarity index 70%
copy from sdk/lib/_internal/pub/test/transformer/fails_to_load_a_pubspec_with_reserved_transformer_test.dart
copy to sdk/lib/_internal/pub_generated/test/transformer/fails_to_load_a_pubspec_with_reserved_transformer_test.dart
index 79f0fcbe82245454d99aaf9ef43045977b49c56f..a9eebf3bdd2a82d2efa7abd3ee4a5bac6d65b79b 100644
--- a/sdk/lib/_internal/pub/test/transformer/fails_to_load_a_pubspec_with_reserved_transformer_test.dart
+++ b/sdk/lib/_internal/pub_generated/test/transformer/fails_to_load_a_pubspec_with_reserved_transformer_test.dart
@@ -16,21 +16,21 @@ main() {
 
   withBarbackVersions("any", () {
     integration("fails to load a pubspec with reserved transformer", () {
-      d.dir(appPath, [
-        d.pubspec({
+      d.dir(appPath, [d.pubspec({
           "name": "myapp",
           "transformers": ["\$nonexistent"]
         }),
-        d.dir("lib", [d.dir("src", [
-          d.file("transformer.dart", REWRITE_TRANSFORMER)
-        ])])
-      ]).create();
+            d.dir(
+                "lib",
+                [d.dir("src", [d.file("transformer.dart", REWRITE_TRANSFORMER)])])]).create();
 
       createLockFile('myapp', pkg: ['barback']);
 
       var pub = startPubServe();
-      pub.stderr.expect(contains('Invalid transformer config: Unsupported '
-          'built-in transformer \$nonexistent.'));
+      pub.stderr.expect(
+          contains(
+              'Invalid transformer config: Unsupported '
+                  'built-in transformer \$nonexistent.'));
       pub.shouldExit(exit_codes.DATA);
     });
   });