Unbork avx512 preduce_mul on MSVC.
MSVC seems to have a buggy implementation of _mm512_reduce_mul_epi64
when the output is negative, instead producing what seems like garbage.
We need to use a different implementation.
MSVC seems to have a buggy implementation of _mm512_reduce_mul_epi64
when the output is negative, instead producing what seems like garbage.
We need to use a different implementation.