Rough and dirty job -- allow concatenation of bytes and arbitrary

buffer-supporting objects (Unicode always excluded), and also of
str and bytes.
(For some reason u"" + b"" doesn't fail, I'll investigate later.)

Objects/object.c

@@ -1347,7 +1347,7 @@ merge_class_dict(PyObject* dict, PyObject* aclass)
 
 /* Helper for PyObject_Dir without arguments: returns the local scope. */
 static PyObject *
-_dir_locals()
+_dir_locals(void)
 {
 	PyObject *names;
 	PyObject *locals = PyEval_GetLocals();
@@ -1892,4 +1892,3 @@ _PyTrash_destroy_chain(void)
 #ifdef __cplusplus
 }
 #endif
-