accept bytes for the AST 'string' type

This is a temporary kludge and all is well in 3.3.
diff --git a/Misc/NEWS b/Misc/NEWS
index 0aa9a11..1281366 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -13,6 +13,9 @@
 - Issue #12326: sys.platform is now always 'linux2' on Linux, even if Python
   is compiled on Linux 3.
 
+- Accept bytes for the AST string type. This is temporary until a proper fix in
+  3.3.
+
 Library
 -------