Function core::arch::wasm32::u64x2_extend_low_u32x4

pub fn u64x2_extend_low_u32x4(a: v128) -> v128

Available on target_family="wasm" and target feature simd128 and WebAssembly only.

将较小 lane vector 的下半部分转换为较大 lane vector，扩展为零。