pkg/compiler: fix imports

pkg/compiler/lib/src/js/rewrite_async.dart

Index: pkg/compiler/lib/src/js/rewrite_async.dart
diff --git a/pkg/compiler/lib/src/js/rewrite_async.dart b/pkg/compiler/lib/src/js/rewrite_async.dart
index 9578f3f7c541dadeb2e1857f563a9968926db271..a70b5d318c4c5ff7933f63d03474fe42c83041a0 100644
--- a/pkg/compiler/lib/src/js/rewrite_async.dart
+++ b/pkg/compiler/lib/src/js/rewrite_async.dart
@@ -4,15 +4,14 @@
 
 library rewrite_async;
 
-import "dart:math" show max;
 import 'dart:collection';
+import "dart:math" show max;
 
 import 'package:js_runtime/shared/async_await_error_codes.dart' as error_codes;
 
-import "js.dart" as js;
-
 import '../common.dart';
 import '../util/util.dart' show Pair;
+import "js.dart" as js;
 
 /// Rewrites a [js.Fun] with async/sync*/async* functions and await and yield
 /// (with dart-like semantics) to an equivalent function without these.