func BytesB(dst, a, b []byte) {
	bytesN(&dst[0], &a[0], &b[0], len(b))
}
BytesB XORs the len(b) bytes in a and b into a
destination slice.
The destination should have enough space.

It's used for encoding small bytes slices (< dozens bytes),
and the slices may not be aligned to 8 bytes or 16 bytes.
If the length is big, it's better to use 'func Bytes(dst, a, b []byte)' instead
for gain better performance.
package xorsimd
func encode(dst []byte, src [][]byte) {
	switch cpuFeature {
	case avx512:
		encodeAVX512(dst, src)
	case avx2:
		encodeAVX2(dst, src)
	default:
		encodeSSE2(dst, src)
	}
	return
}
func Bytes8(dst, a, b []byte) {
	bytes8(&dst[0], &a[0], &b[0])
}
func Bytes16(dst, a, b []byte) {
	bytes16(&dst[0], &a[0], &b[0])
}
func Bytes8Align(dst, a, b []byte) {
	bytes8(&dst[0], &a[0], &b[0])
}
func Bytes16Align(dst, a, b []byte) {
	bytes16(&dst[0], &a[0], &b[0])
}
func BytesA(dst, a, b []byte) {
	bytesN(&dst[0], &a[0], &b[0], len(a))
}