[Bug other/119855] Fixincludes needed for assert.h to support C++26's P2264R7

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119855

--- Comment #11 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Specifically, WG14 N2829 changed assert for C23 and WG21 P2264R7 changed it for
C++26, and the latter includes a solution for the scoped enum problem described
in the glibc bug.