Revert "Abort tracing in type inference in the presence of await."

tests/compiler/dart2js_extra/22868_test.dart

Index: tests/compiler/dart2js_extra/22868_test.dart
diff --git a/tests/compiler/dart2js_extra/22868_test.dart b/tests/compiler/dart2js_extra/22868_test.dart
deleted file mode 100644
index 185e0f6d31fd5b79f85dd0f5ef9f1f3695d89283..0000000000000000000000000000000000000000
--- a/tests/compiler/dart2js_extra/22868_test.dart
+++ /dev/null
@@ -1,12 +0,0 @@
-// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-// Regression test for http://dartbug.com/22868/
-// Ensure that the closure tracer properly handles await.
-
-main() async {
-  var closures = [(x, y) => x + y];
-  print(((await closures)[0])(4, 2));
-}
-