PEP 7 was recently updated to require a C11 compiler (without optional features) to build Python. I propose to now implement this new requirement:

• Build Python with -std=c11 rather than -std=c99
• Use static_assert() of <assert.h>

It's already documented in What's New in Python 3.11:

Building Python now requires a C11 compiler without optional C11 features. (Contributed by Victor Stinner in bpo-46656.

https://docs.python.org/dev/whatsnew/3.11.html#build-changes

• PR: gh-99069: Consolidate checks for static_assert #94766