Fixes needed for FuzzBALL to run sshd

- Adding in a new variable readdir_eof to keep track of End-of-file encountered during previous getdents64(2) calls, the same method(if approved) can be used in getdents(2) as well
- Fixing a bug with pipe(2),pipe2(2)
- returning a hardcoded value of addrlen to stop getnameinfo(3) from crashing sshd
- returning length = 0 for IP_OPTIONS socket option to prevent sshd from crashing
- framework implementations for a few more system calls