[Bug target/80324] _mm512_reduce_xxx type instrinsics are missing

[mail@sven-woop.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80324

--- Comment #1 from Sven Woop <mail@sven-woop.de> ---
These intrinsics are supported by latest ICC and Clang.

Documentation of these can be found here:

https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=reduce&techs=AVX_512

Likely many other reduce intrinsics that show up in the Intrinsics Guide are
missing in GCC too.