Function safe_arch::set_m128d_m256d

#[must_use]pub fn set_m128d_m256d(hi: m128d, lo: m128d) -> m256d

This is supported with target feature avx only.

Set m128d args into an m256d.

let a = set_m128d_m256d(
  set_m128d(3.0, 2.0),
  set_m128d(1.0, 0.0),
).to_array();
assert_eq!(a, [0.0, 1.0, 2.0, 3.0]);