Convert static initializers of `PyTypeObject`s to use C99 Designated (named) initializers

Named initializer are both easier to read and less error prone. There is AFAICT no downside to using them.

However, we have been historically reluctant to change code for purely maintenance. Personally, I think this leads to poorer code quality, but others value cleaner code history more.

In this case I think the readability and correctness advantages are such that we should make this change and accept the inconvenience in version control history.

As a motivating example, take the bool type, PyBool_Type:

PyTypeObject PyBool_Type = {
    PyVarObject_HEAD_INIT(&PyType_Type, 0)
    "bool",
    offsetof(struct _longobject, long_value.ob_digit),  /* tp_basicsize */
    sizeof(digit),                              /* tp_itemsize */
    bool_dealloc,                               /* tp_dealloc */
    0,                                          /* tp_vectorcall_offset */
    0,                                          /* tp_getattr */
    0,                                          /* tp_setattr */
    0,                                          /* tp_as_async */
    bool_repr,                                  /* tp_repr */
    &bool_as_number,                            /* tp_as_number */
    0,                                          /* tp_as_sequence */
    0,                                          /* tp_as_mapping */
    0,                                          /* tp_hash */
    0,                                          /* tp_call */
    0,                                          /* tp_str */
    0,                                          /* tp_getattro */
    0,                                          /* tp_setattro */
    0,                                          /* tp_as_buffer */
    Py_TPFLAGS_DEFAULT,                         /* tp_flags */
    bool_doc,                                   /* tp_doc */
    0,                                          /* tp_traverse */
    0,                                          /* tp_clear */
    0,                                          /* tp_richcompare */
    0,                                          /* tp_weaklistoffset */
    0,                                          /* tp_iter */
    0,                                          /* tp_iternext */
    0,                                          /* tp_methods */
    0,                                          /* tp_members */
    0,                                          /* tp_getset */
    &PyLong_Type,                               /* tp_base */
    0,                                          /* tp_dict */
    0,                                          /* tp_descr_get */
    0,                                          /* tp_descr_set */
    0,                                          /* tp_dictoffset */
    0,                                          /* tp_init */
    0,                                          /* tp_alloc */
    bool_new,                                   /* tp_new */
    .tp_vectorcall = bool_vectorcall,
};

There are a lot of zeros, and a lot of comments to make sure we have the right number of zeros. If one is missing, things go wrong.
Contrast that with the C99 version:

PyTypeObject PyBool_Type = {
    PyVarObject_HEAD_INIT(&PyType_Type, 0)
    .tp_name = "bool",
    .tp_basicsize = offsetof(struct _longobject, long_value.ob_digit),
    .tp_itemsize = sizeof(digit),
    .tp_flags = Py_TPFLAGS_DEFAULT,

    .tp_as_number  = &bool_as_number, 
    .tp_base = &PyLong_Type, 
    .tp_dealloc  = bool_dealloc,  
    .tp_doc = bool_doc,
    .tp_new = bool_new,
    .tp_repr = bool_repr,
    .tp_vectorcall = bool_vectorcall,
};

The code is self describing (no need for comments naming the fields) and is much less error prone. The fields can listed in any order, in this case with the core field first, then the optional fields alphabetically.

首先在 CPython 原始碼中定位 PyBool_Type 和其他靜態 PyTypeObject 初始化器，然後將它們的欄位順序與 PyTypeObject 定義進行比較。在保留其值的同時，將這些初始化器轉換為 C99 指定欄位；當受影響的程式碼能夠使用新的初始化語法成功建置時，即視為完成。