MFp4 bz_ipv6_fast:
MFp4 bz_ipv6_fast:

  Simple yet effective change enabling checksum "offload" on loopback
  for IPv6 to avoid expensive computations.

  Sponsored by:	The FreeBSD Foundation
  Sponsored by:	iXsystems

Reviewed by:	gnn (as part of the whole)
MFC After:	3 days

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase