in C source file to define option features.
Define proper options in each Makefile per ${MACHINE_ARCH} variable instead.
Previously if a host is x86 and it has /usr/mdec/mbr file in its system,
tools fdisk implicitly installs it as mbr bootcode even for !x86 targets.
and install ${TOOLDIR}/bin/${MACHINE_GNU_PLATFORM}-disklabel,
${TOOLDIR}/bin/${MACHINE_GNU_PLATFORM}-fdisk by "reaching over" to
the sources in ${NETBSDSRCDIR}/sbin/{disklabel fdisk}/.
To avoid clashes with a build-host's header files, especially on
*BSD, the host-tools versions of fdisk and disklabel search for
#includes such as disklabel.h, disklabel_acorn.h, disklabel_gpt.h,
and bootinfo.h in a new #includes namespace, nbinclude/. That is,
they #include <nbinclude/sys/disklabel.h>, <nbinclude/machine/disklabel.h>,
<nbinclude/sparc64/disklabel.h>, instead of <sys/disklabel.h> and
such. I have also updated the system headers to #include from
nbinclude/-space when HAVE_NBTOOL_CONFIG_H is #defined.
