[Bug target/113763] [14 Regression] build fails with clang++ host compiler because aarch64.cc uses C++14 constexpr.

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113763

--- Comment #9 from Jonathan Wakely <redi at gcc dot gnu.org> ---
No, _GLIBCXX14_CONSTEXPR only cares about 11 vs 14, not strict vs gnu.