I noticed that NetBSD (-current May 11) doesn't seem to be as careful
as 4.4 about aligning header data.

	For loopback, with no MAC header, everything's word aligned and happy.

	But on Ethernet, NetBSD passes ipintr() a mbuf where mt_data is
aligned to a two-byte boundary but NOT to a four-byte boundary as it is in
straight 4.4. Is this a known and/or fixed problem? Unless I'm missing
something huge, on x86 it would give better total performance to copy the
headers to an aligned buffer, and, on several RISCy systems, it'll panic.

									-Craig