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

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

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

--- Comment #1 from Iain Sandoe <iains at gcc dot gnu.org> ---
I suppose the trivial fix is s/constexpr/const/ (but maybe there's something
more elegant).

If we agree that this is c++14 - only, then maybe we should have a separate bug
that we accept this for c++11.