Fix spelling error.

MFC after:	3 days
Respect and track the enable bit in the PCI configuration address word.
Ignore writes, and return 0xff's, on config accesses when not set.
Behaviour now matches that seen on h/w.

Found with a NetBSD/amd64 guest.

Reviewed by:	tychon
MFC after:	3 weeks
Revert r264907 and r264908:

Restore make-memstick.sh back to its original state to
unbreak booting for machines that do not support GPT.

I have in-progress work to keep the MBR layout and add
the EFI partition, but it is not yet ready, and does
need at least one full release build to be certain it
does not break.

Sponsored by:	The FreeBSD Foundation
Remove device type from the uftdi_devs table, enhance the jtag-skip feature.

Device type and revision is now determined from the bcdDevice field and
doesn't need to be in the table at all.  The feature that skips creation
of /dev/ttyU* entries for jtag and gpio interfaces is enhanced:

 - The feature is now optional, but enabled by default.  A tunable and
   sysctl are available to control it: hw.usb.uftdi.skip_jtag_interfaces.
 - We no longer assume interface #0 is the only jtag interface.  Up to
   eight interfaces per chip can be flagged as jtag.  (Current ftdi chips
   support a max of 4 interfaces; this leaves room for growth.)
 - Some manufacturers don't change the product ID or use the same ID for
   different devices intended for both serial-comms and jtag/gpio use.
   Often while the product ID is the same, the product name string is
   different, so it's now possible to search for the product name in a
   table of strings and get the set of non-tty interfaces from that table.
Remove NO_CTF, exccept as an undocumented compatibility
option. Convert all other uses to MK_CTF=no. Set MK_CTF=no rather than
the indirect WITHOUT_CDDL in filemon regression. It is expected that
NO_CTF will be removed in FreeBSD 12 entirely.
Eliminate last vestigies of NO_MAN= in the tree. Also, remove
ineffectual NOMAN= lines. These don't change the build at all.
Kill last remaining NO_INSTALLLIB in tree by converting it over to
MK_INSTALLIB=no.
NO_DEBUG_FILES -> MK_DEBUG_FILES=no in last remaining place.
Spell NO_PROFILE= as MK_PROFILE=no.
Now that all the NO_foo expressed in this loop have been removed from
the tree, start warning that NO_foo is deprecated. It was supposed to
be gone from the tree as a user-setting a long time ago...
Eliminate NO_INCS. It is used one place, and MK_TOOLCHAIN=no will
handle the job just as well. Opt for simplicity rather than one more
option.
Split up the options into those used only by bsd.mk.* or sys.mk and
the rest. Add note of caution for the surprises that popped up. MK_SSP
is the only one used by sys.mk, and it likely needs even extra
attention.
Generalize FOO.clang to FOO.${COMPILER_TYPE}. There's no reason these
need to be clang specific. Also generalize things a bit.
Fix indentation for diff reduction with commits to follow.

Sponsored by:	The FreeBSD Foundation
The FTDI product ID we've been calling BEAGLEBONE is actually TI XDS100V2,
a jtag debugging product, which was used on early Beaglebone boards (later
boards used a standard FTDI 2232C product ID).  Change the name accordingly,
and also add an entry for XDS100V3, the latest version of that product
which has its own new product ID number.
Enable LLDB by default on amd64

Sponsored by:	DARPA, AFRL
Add THR and LIBRT signals missing in libc/kernel

Sponsored by:	DARPA, AFRL
Clean up error reporting

Omit "too many sections" warnings if the ELF file is not dynamically
linked (and is therefore skipped anyway), and otherwise output it only
once.  An errant core file would previously cause kldxref to output a
number of warnings.

Sponsored by:	The FreeBSD Foundation
Drop explicit unsigned from FD_SETSIZE constant

FD_SETSIZE is often used as an argument to select or compared with an
integer file descriptor.  Rather than force 3rd party software to add
explicit casts, just make it a plain constant as on other operating
systems.

Sponsored by:	The FreeBSD Foundation
Report boot method (BIOS/UEFI) via sysctl machdep.bootmethod