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

sdk/lib/_internal/pub_generated/test/global/run/mode_test.dart

Index: sdk/lib/_internal/pub_generated/test/global/run/mode_test.dart
diff --git a/sdk/lib/_internal/pub/test/global/run/mode_test.dart b/sdk/lib/_internal/pub_generated/test/global/run/mode_test.dart
similarity index 74%
copy from sdk/lib/_internal/pub/test/global/run/mode_test.dart
copy to sdk/lib/_internal/pub_generated/test/global/run/mode_test.dart
index 9a5a838de0f3ecfddc4cfab8c36ea526034d8f21..fdf4b8a35f24db13a3d52931a3e2229ddd883a07 100644
--- a/sdk/lib/_internal/pub/test/global/run/mode_test.dart
+++ b/sdk/lib/_internal/pub_generated/test/global/run/mode_test.dart
@@ -27,20 +27,24 @@ class DartTransformer extends Transformer {
 
 main() {
   initConfig();
-  integration('runs a script in an activated package with customizable modes',
+  integration(
+      'runs a script in an activated package with customizable modes',
       () {
     servePackages((builder) {
       builder.serveRepoPackage("barback");
 
-      builder.serve("foo", "1.0.0",
-          deps: {"barback": "any"},
-          pubspec: {"transformers": ["foo/src/transformer"]},
+      builder.serve("foo", "1.0.0", deps: {
+        "barback": "any"
+      }, pubspec: {
+        "transformers": ["foo/src/transformer"]
+      },
           contents: [
-        d.dir("lib", [d.dir("src", [
-          d.file("transformer.dart", TRANSFORMER),
-          d.file("primary.in", "")
-        ])])
-      ]);
+              d.dir(
+                  "lib",
+                  [
+                      d.dir(
+                          "src",
+                          [d.file("transformer.dart", TRANSFORMER), d.file("primary.in", "")])])]);
     });
 
     schedulePub(args: ["global", "activate", "foo"]);