Function core::arch::wasm64::u8x16_sub_sat

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

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

减去两个 128 位 vectors，就好像它们是两个包装的 16 个 8 位无符号整数，溢出时饱和到 0.