Various simd_x86 functions that handle double need to be adjusted to
match 64-bit long double as well.
Introduce __is_x86_ps<_Tp>() and __is_x86_pd<_Tp>() and use them
instead of is_same_v<_Tp, float> and is_same_v<_Tp, double>,
respectively.
for libstdc++-v3/ChangeLog
PR libstdc++/124657
* include/experimental/bits/simd_x86.h
(__is_x86_ps<_Tp>): New. Replace is_same_v<_Tp, float> with it.
(__is_x86_pd<_Tp>): New. Replace is_same_v<_Tp, double> with it.
8b52a53987