[Bug libstdc++/124657] experimental/simd/pr109261_constexpr_simd.cc fails to compile on x86_64 with -mlong-double-64

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124657

--- Comment #1 from Alexandre Oliva <aoliva at gcc dot gnu.org> ---
Err...  The symptom I described is with
https://gcc.gnu.org/pipermail/gcc-patches/2026-March/711318.html applied. 
Without it, we get long double rejected much earlier.