/usr/include/iraf.h is in iraf-dev 2.16.1+2018.03.10-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/include/../lib/iraf/unix/hlib/libc/iraf.h
/usr/include/../lib/iraf/unix/hlib/libc/iraf.h