Function core::arch::wasm32::i16x8_extend_high_i8x16

pub fn i16x8_extend_high_i8x16(a: v128) -> v128

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

将较小 lane vector 的高一半转换为较大 lane vector，并对其进行符号扩展。