Backport fix to a test from cytoolz. pytoolz/cytoolz#105

Blacklist special Cython functions when checking for introspection.

Author: eriknw

toolz/tests/test_inspect_args.py

@@ -409,6 +409,8 @@ def add_blacklist(mod, attr):
     def is_missing(modname, name, func):
         if name.startswith('_') and not name.startswith('__'):
             return False
+        if name.startswith('__pyx_unpickle_') or name.endswith('_cython__'):
+            return False
         try:
             if issubclass(func, BaseException):
                 return False