Re: [PATCH v4 0/2] MR5915: include: Tweak atexit and cpuid declarations, guard DECLSPEC_UUID definition.

[Rémi Bernon (＠rbernon)]

I guess `(!defined(__has_builtin) || __has_builtin(__cpuidex))` is a bit awkward after defining to 0 if it's not defined, but it's meant to detect MSVC vs clang. Then I don't know if that's necessary here, as I suspect actual MSVC would never get there?