We have fixed resolv.h and net/if.h in ZBX-2666, but there are many more headers that we do not detect properly.

For instance, on FreeBSD 4.2 configure complains about the following headers:

configure:4470: WARNING: sys/mount.h: present but cannot be compiled
configure:4470: WARNING: sys/proc.h: present but cannot be compiled
configure:4470: WARNING: net/if_mib.h: present but cannot be compiled
configure:4470: WARNING: sys/user.h: present but cannot be compiled
configure:4470: WARNING: sys/ucontext.h: present but cannot be compiled
configure:4470: WARNING: devstat.h: present but cannot be compiled