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

sdk/lib/_internal/pub_generated/lib/src/validator/utf8_readme.dart

Index: sdk/lib/_internal/pub_generated/lib/src/validator/utf8_readme.dart
diff --git a/sdk/lib/_internal/pub/lib/src/validator/utf8_readme.dart b/sdk/lib/_internal/pub_generated/lib/src/validator/utf8_readme.dart
similarity index 81%
copy from sdk/lib/_internal/pub/lib/src/validator/utf8_readme.dart
copy to sdk/lib/_internal/pub_generated/lib/src/validator/utf8_readme.dart
index 9f30d65599d7668fecd5c13806edeb3d5c30742e..c3e2bf7617ac390f2db6d278e931327aeb7c3d9a 100644
--- a/sdk/lib/_internal/pub/lib/src/validator/utf8_readme.dart
+++ b/sdk/lib/_internal/pub_generated/lib/src/validator/utf8_readme.dart
@@ -14,7 +14,7 @@ import '../validator.dart';
 /// Validates that a package's README is valid utf-8.
 class Utf8ReadmeValidator extends Validator {
   Utf8ReadmeValidator(Entrypoint entrypoint)
-    : super(entrypoint);
+      : super(entrypoint);
 
   Future validate() {
     return new Future.sync(() {
@@ -25,9 +25,9 @@ class Utf8ReadmeValidator extends Validator {
         // UTF8.decode doesn't allow invalid UTF-8.
         UTF8.decode(bytes);
       } on FormatException catch (_) {
-        warnings.add("$readme contains invalid UTF-8.\n"
-            "This will cause it to be displayed incorrectly on "
-                "pub.dartlang.org.");
+        warnings.add(
+            "$readme contains invalid UTF-8.\n"
+                "This will cause it to be displayed incorrectly on " "pub.dartlang.org.");
       }
     });
   }