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

sdk/lib/_internal/pub_generated/test/hosted/fail_gracefully_on_missing_package_test.dart

Index: sdk/lib/_internal/pub_generated/test/hosted/fail_gracefully_on_missing_package_test.dart
diff --git a/sdk/lib/_internal/pub/test/hosted/fail_gracefully_on_missing_package_test.dart b/sdk/lib/_internal/pub_generated/test/hosted/fail_gracefully_on_missing_package_test.dart
similarity index 84%
copy from sdk/lib/_internal/pub/test/hosted/fail_gracefully_on_missing_package_test.dart
copy to sdk/lib/_internal/pub_generated/test/hosted/fail_gracefully_on_missing_package_test.dart
index df53819de683b7bcefd8bb09ce205d22fbb8f552..cfb153c6495e71430ca552475342465253b6a463 100644
--- a/sdk/lib/_internal/pub/test/hosted/fail_gracefully_on_missing_package_test.dart
+++ b/sdk/lib/_internal/pub_generated/test/hosted/fail_gracefully_on_missing_package_test.dart
@@ -16,13 +16,14 @@ main() {
     integration('fails gracefully if the package does not exist', () {
       serveNoPackages();
 
-      d.appDir({"foo": "1.2.3"}).create();
+      d.appDir({
+        "foo": "1.2.3"
+      }).create();
 
       pubCommand(command, error: new RegExp(r"""
 Could not find package foo at http://localhost:\d+\.
 Depended on by:
-- myapp""", multiLine: true),
-          exitCode: exit_codes.UNAVAILABLE);
+- myapp""", multiLine: true), exitCode: exit_codes.UNAVAILABLE);
     });
   });
 }