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/language/constructor_name_clash_lib.dart b/tests/compiler/dart2js_extra/22868_test.dart
similarity index 52%
copy from tests/language/constructor_name_clash_lib.dart
copy to tests/compiler/dart2js_extra/22868_test.dart
index 46ea6c0b3c621fcd1827750c10de66980b5b3057..185e0f6d31fd5b79f85dd0f5ef9f1f3695d89283 100644
--- a/tests/language/constructor_name_clash_lib.dart
+++ b/tests/compiler/dart2js_extra/22868_test.dart
@@ -2,13 +2,11 @@
 // 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.
 
-library lib;
+// Regression test for http://dartbug.com/22868/
+// Ensure that the closure tracer properly handles await.
 
-var global = 0;
-
-class A {
-  A() {
-    global += 10;
-    try {} catch(e) {} // no inline
-  }
+main() async {
+  var closures = [(x, y) => x + y];
+  print(((await closures)[0])(4, 2));
 }
+