DONE
Test linux_sendfile using linuxulator with these linux binaries both as 32 and 64 bit versions:
* TCP client/server program: One uses sendfile to send file
* UDP client/server program: One uses sendfile to send file
* Use sendfile to copy a file to another file.
In each case sendfile is tested multiple times using different parameters to check the correct error code is returned.
TODO
Test it with linux binary of nginx which is the original use case