posix_madvise if MADV_SEQUENTIAL or POSIX_MADV_SEQUENTIAL exist. As it
is a hint for the VM subsystem, it doesn't hurt if neither is provided.
Based on input from Sean Boudreau.
OpenBSD changes as nbpatch-20080910.
This package is intended to replace devel/patch as dependency for the
infrastructure. GNU patch has issues both with very long lines and with
asymmetric context, making it impossible to use in some situations.