Note that __bsdi__s_/_i_/_os_/__ has moved this file to dev/ic/ and
has completely removed the non-compiling function from pdq_ifsubr.c and
has completely removed this function and placed it into netinet/if_ether.c
(if, in fact, it wasn't there the whole time). I was tempted to simply
remove this __bsdi__only__ function.
The function is arp_ifinit().
PR: kern/7903