[Bug target/121606] -march=native on AVX10.1 capable host warns about -mno-evex512

[marko.makela at mariadb dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121606

--- Comment #11 from Marko Mäkelä <marko.makela at mariadb dot com> ---
I apologize for my inaccurate claim that the AMD Zen 5 would be capable of full
AVX10.1. In any case, EVEX512 definitely is supported.

Based on https://en.wikipedia.org/wiki/Advanced_Vector_Extensions#AVX10 and the
table in https://en.wikipedia.org/wiki/AVX-512#CPUs_with_AVX-512 it looks like
the AMD Zen 5 microarchitecture is missing the FP16 feature. If the related
instructions cannot be "accidentally" emitted for target("avx10.1"), only by
specific intrinsic functions or inline assembler code, then there should be no
issue related to that. (GCC is removing the more specific AVX-512 feature
flags; that is why the broader "avx10.1" needs to be used.)