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

sdk/lib/_internal/pub_generated/test/build/allows_arbitrary_modes_test.dart

Index: sdk/lib/_internal/pub_generated/test/build/allows_arbitrary_modes_test.dart
diff --git a/sdk/lib/_internal/pub/test/build/allows_arbitrary_modes_test.dart b/sdk/lib/_internal/pub_generated/test/build/allows_arbitrary_modes_test.dart
similarity index 74%
copy from sdk/lib/_internal/pub/test/build/allows_arbitrary_modes_test.dart
copy to sdk/lib/_internal/pub_generated/test/build/allows_arbitrary_modes_test.dart
index e9f4096cdedbef829126f7f5166f515d00c6ffe3..ef8fd723aa2ec4edca2fddbc023516d1ca468339 100644
--- a/sdk/lib/_internal/pub/test/build/allows_arbitrary_modes_test.dart
+++ b/sdk/lib/_internal/pub_generated/test/build/allows_arbitrary_modes_test.dart
@@ -31,30 +31,20 @@ main() {
   initConfig();
   withBarbackVersions("any", () {
     integration("allows user-defined mode names", () {
-      d.dir(appPath, [
-        d.pubspec({
+      d.dir(appPath, [d.pubspec({
           "name": "myapp",
           "transformers": ["myapp/src/transformer"]
         }),
-        d.dir("lib", [d.dir("src", [
-          d.file("transformer.dart", TRANSFORMER)
-        ])]),
-        d.dir("web", [
-          d.file("foo.txt", "foo")
-        ])
-      ]).create();
+            d.dir("lib", [d.dir("src", [d.file("transformer.dart", TRANSFORMER)])]),
+            d.dir("web", [d.file("foo.txt", "foo")])]).create();
 
       createLockFile('myapp', pkg: ['barback']);
 
       schedulePub(args: ["build", "--mode", "depeche"]);
 
-      d.dir(appPath, [
-        d.dir('build', [
-          d.dir('web', [
-            d.file('foo.out', 'depeche')
-          ])
-        ])
-      ]).validate();
+      d.dir(
+          appPath,
+          [d.dir('build', [d.dir('web', [d.file('foo.out', 'depeche')])])]).validate();
     });
   });
 }