This restrict ARP handling to MAC and IP addresses but in practice we need
only this case anyway and other cases are very rar if exist at all. It makes
code much simpler and less error-prone.
Origin: upstream, http://git.savannah.gnu.org/cgit/grub.git/commit/?id=63034d32612dd34f577605dfa8b417ee9144d8cb
Last-Update: 2015-04-06
Patch-Name: arp_icmp_oversize_handling.patch