WriteCompressed() nagative types did not tell big endian and little endian cases

[Kiddinglife]

this function only works as we thought on nagative types in little endian system. That is it will compresss the 11111111 or 00000000, however, for big endian, it does not compresss in a correct way bacause the byte of nagative type located at low memeory adresss in big endian system are high byte.