Function safe_arch::add_horizontal_i32_m128i

#[must_use]pub fn add_horizontal_i32_m128i(a: m128i, b: m128i) -> m128i

This is supported with target feature ssse3 only.

Add horizontal pairs of i32 values, pack the outputs as a then b.

let a = m128i::from([1, 2, 3, 4]);
let b = m128i::from([5, 6, 7, 8]);
let c: [i32; 4] = add_horizontal_i32_m128i(a, b).into();
assert_eq!(c, [3, 7, 11, 15]);