Function safe_arch::zero_extend_m128d

#[must_use]pub fn zero_extend_m128d(a: m128d) -> m256d

This is supported with target feature avx only.

Zero extend an m128d to m256d

let a = zero_extend_m128d(m128d::from_array([1.0, 2.0])).to_array();
assert_eq!(a, [1.0, 2.0, 0.0, 0.0]);