Use larger queue sizes for faster NICs

Use larger queue sizes for 1GbE and 10GbE interfaces.  This fixes
soft overflow drops on a 10GbE interface I've been using.

Signed-off-by: Andrew Gallatin <gallatin@google.com>
Enable UDP checksum offload.

Enable UDP csum offload for IPv4.  This is good for a few
hundred Mb/s performance improvement for netperf -tUDP_STREAM
tests using a 10GbE NIC.

Signed-off-by: Andrew Gallatin <gallatin@google.com>
Increase the UDP buffer size.

Signed-off-by: Andrew Gallatin <gallatin@google.com>
Don't zero new blocks.

Avoid zeroing new blocks.  This has a real cost at 10GbE speeds

Signed-off-by: Andrew Gallatin <gallatin@google.com>
Speed up memmove on x86

Take an asm bcopy (which has the same overlapping semantics
as memmove) from FreeBSD.  This speeds up netperf by anywhere
from 25-40% on x86_64

Note:  I also brought in a copy for i686, but i686 does not
compile due to other prolems in the tree, so I was unable to test it.
Speed up ptclbsum

Bring in the 64-bit checksum routine that originated in
NetBSD/alpha, and then came into FreeBSD/alpha and was used for
many of its 64-bit platforms including amd64.  This speeds
up non-checksum offload paths (like UDP transmit) by about 5%.