Function core::arch::wasm::u8x16_sub_sat

pub fn u8x16_sub_sat(a: v128, b: v128) -> v128

This is supported on target_family="wasm" and target feature simd128 only.

将两个 128 位 vectors 相减，就好像它们是两个包装的 16 个 8 位无符号整数一样，溢出时饱和为 0。