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

sdk/lib/_internal/pub_generated/test/downgrade/unlock_dependers_test.dart

Index: sdk/lib/_internal/pub_generated/test/downgrade/unlock_dependers_test.dart
diff --git a/sdk/lib/_internal/pub/test/downgrade/unlock_dependers_test.dart b/sdk/lib/_internal/pub_generated/test/downgrade/unlock_dependers_test.dart
similarity index 67%
copy from sdk/lib/_internal/pub/test/downgrade/unlock_dependers_test.dart
copy to sdk/lib/_internal/pub_generated/test/downgrade/unlock_dependers_test.dart
index c329bdb28a9b156ffb49e1000905e2dd7c21bb9c..4140a5fde516d500d8f5da8234ba04b90f9a27ba 100644
--- a/sdk/lib/_internal/pub/test/downgrade/unlock_dependers_test.dart
+++ b/sdk/lib/_internal/pub_generated/test/downgrade/unlock_dependers_test.dart
@@ -9,14 +9,20 @@ import '../test_pub.dart';
 
 main() {
   initConfig();
-  integration("downgrades a locked package's dependers in order to get it to "
-      "min version", () {
+  integration(
+      "downgrades a locked package's dependers in order to get it to " "min version",
+      () {
     servePackages((builder) {
-      builder.serve("foo", "2.0.0", deps: {"bar": ">1.0.0"});
+      builder.serve("foo", "2.0.0", deps: {
+        "bar": ">1.0.0"
+      });
       builder.serve("bar", "2.0.0");
     });
 
-    d.appDir({"foo": "any", "bar": "any"}).create();
+    d.appDir({
+      "foo": "any",
+      "bar": "any"
+    }).create();
 
     pubGet();
 
@@ -26,7 +32,9 @@ main() {
     }).validate();
 
     servePackages((builder) {
-      builder.serve("foo", "1.0.0", deps: {"bar": "any"});
+      builder.serve("foo", "1.0.0", deps: {
+        "bar": "any"
+      });
       builder.serve("bar", "1.0.0");
     });