Added a comment explaining what is being tested for

tests/regress/ensure_typedef_consts_generated.py

@@ -1,3 +1,10 @@
+"""See https://github.com/unicorn-engine/unicorn/issues/161
+
+Ensure that constants which are specified via a typedef, rather than an enum,
+are included in the bindings by the script for autogenerating mappings for
+constants.
+"""
+
 import unicorn
 
 try: