fix parser crash

--HG--
extra : rebase_source : ac66b38753ea5b4ea9d47ff475ebbf33b19b7c49

Cython/Compiler/Parsing.py

@@ -2462,7 +2462,7 @@ def p_c_arg_decl(s, ctx, in_pyfunc, cmethod_flag = 0, nonempty = 0,
         annotation = p_test(s)
     if s.sy == '=':
         s.next()
-        if 'pxd' in s.level:
+        if 'pxd' in ctx.level:
             if s.sy not in ['*', '?']:
                 error(pos, "default values cannot be specified in pxd files, use ? or *")
             default = ExprNodes.BoolNode(1)