vkernel - Add debugging

* Provide more information when interrupting to the db> prompt.
kernel - Cleanup SWB_NPAGES

* Remove the conditional for the SWB_NPAGES #define so the swblock
  structure remains consistent.  Remove the override in swap_pager.c.

* Previous code was confusing, but harmless.

Reported-by: Enjolras
bnx: Remove remainder of BCM5906
bnx: Defer interrupt allocation until chip reset is done
bnx: It does not make sense to have ret-ring size larger than prod-ring
bnx: Regroup TX related fields into TX ring struct
bnx: NIC based TX rings are only applicable to chips before 5705
libc: Add a few missing xdr functions

Obtained-from: FreeBSD
re: Disable IP header checksum offloading on 8168C/8168CP

These chips will generate wrong IP header checksum if IP options exist.

Obtained-from: FreeBSD
bnx: Turn softc SHORTDMA flag into per TX ring flag

Avoid extra softc accessing during transmission.
bnx: Make "force defrag" as TX ring flag
bnx: Make sure that all of the TX rings receive tx_wreg update
lock(1): Do not require 'options COMPAT_43' in the kernel config.

We commented out COMPAT_43 in our configs some time ago, which broke
lock(1) that needed TIOCGETP and TIOCSETP ioctls which are only
available with COMPAT_43.

This commit converts lock(1) to use tcgetattr(3) and tcsetattr(3),
along with some minor cleanups.

Reported-by:  noway on #dragonflybsd
Submitted-by: Joris Giovannangeli <joris@giovannangeli.fr>
Taken-from:   FreeBSD
kernel: Unbreak building kernels that have 'options BNX_TSO_DEBUG'.
kernel: Remove 'options COMPAT_SUNOS'.

It was supposed to provide binary compatibility with SunOS 4.x for the
sparc32 port of 4.4BSD.
libc/libc_r: Remove some obsolete comments.
libc: Bring back warnings to libc.

To disable warnings for the gdtoa sources only, the tweaking of the
CWARNFLAGS has to come _after_ <bsd.lib.mk> is included.

Therefore, it has to be done in libc's Makefile instead of its
Makefile.inc.

Before this commit warnings were completely disabled for libc due
to '-w' passed to every command line.

Also reset WARNS back to 0 since right now, libc doesn't even pass
WARNS=1.
libc: Fix -Wold-style-definition.
libc: Fix -Wunused-variable.
libc: Fix -Wformat.