x86: use template for AVX/AVX512 floating point comparison insns

x86: use template for AVX/AVX512 floating point comparison insns

These all follow an almost common pattern, again with the exception of
being commutative, which can be easily taken care of.

Note that, as an intended side effect (and in fact one of the reason to
introduce templates), AVX long-form pseudo-ops get introduced alongside
the already existing AVX512 ones.