[Csv] non-portable initialisation of types in _csv.c

[Skip Montanaro]

    John> static PyTypeObject Dialect_Type = {
    John>    /* aarrgghh PyObject_HEAD_INIT(&PyType_Type) */
    John>    PyObject_HEAD_INIT(NULL)
    John>    0,                                      /* ob_size */

John,

Thanks, is this a Windows thing?  What about the head initializer for the
Reader_Type and Writer_Type types?

Skip