Function safe_arch::move_low_high_m128

#[must_use]pub fn move_low_high_m128(a: m128, b: m128) -> m128

This is supported with target feature sse only.

Move the low lanes of b to the high lanes of a, other lanes unchanged.

let a = m128::from_array([1.0, 12.0, 3.0, 4.0]);
let b = m128::from_array([8.0, 6.0, 7.0, 8.5]);
let c = move_low_high_m128(a, b).to_array();
assert_eq!(c, [1.0, 12.0, 8.0, 6.0]);