Store the async-await compiled pub code directly in the repo.

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

+library pub_tests;
+import 'package:scheduled_test/scheduled_test.dart';
+import '../descriptor.dart' as d;
+import '../test_pub.dart';
+import '../serve/utils.dart';
+main() {
+  initConfig();
+  withBarbackVersions("any", () {
+    integration(
+        "fails to load an unconfigurable transformer when config is " "passed",
+        () {
+      d.dir(appPath, [d.pubspec({
+          "name": "myapp",
+          "transformers": [{
+              "myapp/src/transformer": {
+                'foo': 'bar'
+              }
+            }]
+        }),
+            d.dir(
+                "lib",
+                [d.dir("src", [d.file("transformer.dart", REWRITE_TRANSFORMER)])])]).create();
+      createLockFile('myapp', pkg: ['barback']);
+      var pub = startPubServe();
+      pub.stderr.expect(
+          startsWith('No transformers that accept configuration ' 'were defined in '));
+      pub.shouldExit(1);
+    });
+  });
+}