Fix do-while with await in condition

tests/language/regress_22777_test.dart

Index: tests/language/regress_22777_test.dart
===================================================================
--- tests/language/regress_22777_test.dart	(revision 0)
+++ tests/language/regress_22777_test.dart	(working copy)
@@ -0,0 +1,43 @@
+// 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.
+
+import "package:async_helper/async_helper.dart";
+import "package:expect/expect.dart";
+
+var a = 0;
+
+testSync () {
+  do {
+    continue;
+  } while (throw "Error");
+  a = 100;
+}
+
+testAsync() async {
+  do {
+    continue;
+  } while (await (throw "Error"));
+  a = 100;
+}
+
+test() async {
+  try {
+    testSync();
+  } catch (e) {
+    Expect.equals(e, "Error");
+  }
+  Expect.equals(a, 0);
+
+  try {
+    await testAsync();
+  } catch (e) {
+    Expect.equals(e, "Error");
+  }
+  Expect.equals(a, 0);
+}
+
+main() {
+  asyncStart();
+  test().then((_) => asyncEnd());
+}