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 a562d29..4df888f 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,9 @@
 Core and Builtins
 -----------------
 
+- Accept bytes for the AST string type. This is temporary until a proper fix in
+  3.3.
+
 - Issue #9200: The str.is* methods now work with strings that contain non-BMP
   characters even in narrow Unicode builds.