Handle type literals correctly with deferred loading and await.

tests/language/deferred_regression_28678_lib.dart

Index: tests/language/deferred_regression_28678_lib.dart
diff --git a/tests/language/deferred_regression_28678_lib.dart b/tests/language/deferred_regression_28678_lib.dart
new file mode 100644
index 0000000000000000000000000000000000000000..f36c206124c563754bbffbb298bcb207658dd674
--- /dev/null
+++ b/tests/language/deferred_regression_28678_lib.dart
@@ -0,0 +1,7 @@
+// Copyright (c) 2017, 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.
+
+var v;
+
+class Clazz { }