[Bug target/85100] __builtin_cpu_supports avx does not verify OS supports it

[ubizjak at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85100

--- Comment #6 from Uroš Bizjak <ubizjak at gmail dot com> ---
(In reply to Richard Biener from comment #2)
> I think this is on purpose and unlikely to change.

No, __builtin_cpu_supports is used to enable parts that are able to execute
relevant instructions. So, HJ's patch is the way to go.