Merge riastradh-drm2 to HEAD.

Use MACHINE_CPU with m68k (m68000 will not be matched due to MKPIC=no)

branches: 1.26.2;
There are other little endian arm machine_arches other than "arm"

branches: 1.25.2;
Revert last, it breaks the tricks xsrc uses.

Remove SHLIBINSTALLDIR and SHLINKINSTALLLIBDIR. Add rpath entries, if
SHLIBDIR differs from /usr/lib.

branches: 1.23.6;
remove almost all the ability to build netbsd with an a.out target.
we're ELF now, and there are many missing checks against OBJECT_FMT.
if we ever consider switching, the we can figure out what new ones
we need but for now it's just clutter.

this doesn't remove any of the support for exec_aout or any actually
required-for-boot a.out support, only the ability to build a netbsd
release in a.out format. ie, most of this code has been dead for
over a decade.

i've tested builds on vax, amd64, i386, mac68k, macppc, sparc, atari,
amiga, shark, cats, dreamcast, landisk, mmeye and x68k. this covers
the 5 MACHINE_ARCH's affected, and all the other arch code touched.
it also includes some actual run-time testing of sparc, i386 and
shark, and i performed binary comparison upon amiga and x68k as well.


some minor details relevant:
- move shlib.[ch] from ld.aout_so into ldconfig proper, and cut them
down to only the parts ldconfig needs
- remove various unused source files
- switch amiga bootblocks to using elf2bb.h instead of aout2bb.h

make MKPIC=no builds work on i368, shark, vax, pmax, sgimips, sparc,
maybe all mips and all arm as well.

branches: 1.21.32; 1.21.40;
MKDYNAMICROOT for a.out

Use ${NETBSDSRCDIR}/some/path instead of ${.CURDIR}/../../some/path

Also build ldconfig is MACHINE_ARCH is arm or vax buf OBJECT_FMT=ELF

Make and install ldconfig on ELF m68k ports.

Modification to previous: only build for ports that are a.out or used
to be a.out. No sense in building for ports that never were a.out.

Build this on ELF as well. When on an ELF system, only look in
_PATH_EMUL_AOUT/etc/ld.so.conf.

branches: 1.15.10;
Only build ldconfig on a.out platforms. Everyone else still builds the
manual page.

Adapt to new location in `src/sbin'.

allow LDSTATIC definition to be overridden by bsd.own.mk/mk.conf

install all man pages.

Ld directory reorganization:
- separate out the common files used by rtld ldd ld
- move machine dependent files into arch
- move ld in its own directory
- factor out .PATH and CFLAGS common to all Makefiles

complete remove special search dirs, use NetBSD Id tag.

specify man pages the new way.

Conversion to err()/warn() for error reports.

Minor cleanup.

Use MACHINE_ARCH.

*** empty log message ***

MACHINE_ARCH support

Remove ${DESTDIR} from BINDIR.

add -static to 'LDFLAGS', as it goes in /sbin

Utility to maintain shared library lookup "hints".
Does business in `/var/run/ld.so.hints'.