Function safe_arch::add_saturating_i8_m128i

#[must_use]pub fn add_saturating_i8_m128i(a: m128i, b: m128i) -> m128i

This is supported with target feature sse2 only.

Lanewise saturating a + b with lanes as i8.

let a = m128i::from([
  i8::MAX, i8::MIN, 3, 4, -1, -2, -3, -4,
  3, 4, -1, -2, -1, -2, -3, -4,
]);
let b = m128i::from([
  i8::MAX, i8::MIN, 7, 8, -15, -26, -37, 48,
  7, 8, -15, -26, -15, -26, -37, 48,
]);
let c: [i8; 16] = add_saturating_i8_m128i(a, b).into();
assert_eq!(
  c,
  [
    i8::MAX, i8::MIN, 10, 12, -16, -28, -40, 44,
    10, 12, -16, -28, -16, -28, -40, 44
  ]
);