build fails with `--enable-pystats --with-pydebug` (use of Py_SIZE on PyLongObject)

[carljm]

> ./configure --enable-pystats --with-pydebug
> make -j
...
_bootstrap_python: ../../cpython/Include/object.h:215: Py_SIZE: Assertion `ob->ob_type != &PyLong_Type' failed.

It looks like #102464 missed removing this use of Py_SIZE on a PyLongObject because it is gated behind #ifdef Py_STATS.

When debug is enabled, this causes an assertion to fail. Without assertions, I think it can cause inaccurate stats collection for STORE_SUBSCR specialization failures.

Linked PRs

• gh-104184: fix building --with-pydebug --enable-pystats #104217