Function safe_arch::set_splat_i8_m256i

#[must_use]pub fn set_splat_i8_m256i(i: i8) -> m256i

This is supported with target feature avx only.

Splat an i8 arg into an m256i lane.

let a: [i8; 32] = set_splat_i8_m256i(56).into();
assert_eq!(a, [56_i8; 32]);