[issue41617] __builtin_bswap16 is used without checking it is supported

[STINNER Victor]

Change by STINNER Victor <vstinner at python.org>:


----------
pull_requests: +22158
pull_request: https://github.com/python/cpython/pull/23262

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue41617>
_______________________________________