risc-v: Fix nlist on ELF64

The define __riscv64 is not provided (anymore?), so use _LP64 to determine
if nlist support for ELF64 should be added.

This fixes a problem pointed to me by he@

riscv64# pstat -sh -N /netbsd
pstat: kvm_nlist: bad namelist
riscv64#

in that it now doesn't fail with "bad namelist". Other problems with pstat
seem to exist, however.

branches: 1.26.8;
Be less of a minefield for new architectures. They're not going to be a.out.
Remove sh5, long gone.
(Hopefully nothing hits the #else case)

branches: 1.25.16;
add or1k

missing ia64.

Add entries for riscv and aarch64. This lets the former build
complete and gets the latter close to the end.

Use C89 definitions.
Remove use of __P

branches: 1.21.6;
cleanup format of #ifdef

If not using O32 on mips, we need to read ELF64 symbols too.

Introduce a new accessor macro N_NAME() to access the n_name field
in struct nlist, since it's accessed differently depending on
whether we do a.out or not. Use this macro as appropriate in the
nlist* functions.
Also replace some includes of <a.out.h> with <nlist.h>, to fix build
problem for mips.

Only include <sys/exec_aout.h> if NLIST_AOUT is defined.
Don't define NLIST_AOUT for mips anymore.

branches: 1.17.46;
netbsd.org->NetBSD.org

Enable ELF32 nlist (as well as ELF64) for x86-64.

Add SH5 support. (Missed these during the last sweep of my local tree)

Added hppa support (some of it incomplete) to lib/csu, lib/libc,
and lib/libkvm.

Use NLIST_ELF64 for x86_64.

Enable ELF32 support for VAX.

branches: 1.11.2;
Make both ARM ports support both NLIST_AOUT and NLIST_ELF32.

sweep of my licenses (userland files w/o only my copyright) for
consistency. (no functional changes)

fix up NetBSD RCS Ids to match the standard, and the leading comment as
to match as well. No functional changes.

branches: 1.8.2;
Initial commit of arm26 port

nlist for COFF

Sync w/ kvm_mkdb.

Add Elf32 support for i386, m68k, and sparc.

MIPS: a.out, ecoff, and elf nlist support
PowerPC: a.out and elf nlist support

kill recently added 'check' functions, since they only add code to be more
expensive, i.e. they save nothing and add code.

slightly tune what gets compiled in: On the Alpha, we need ECOFF and
ELF64. On other architectures only include a.out support, since we don't
know whether or not they'll have the headers necessary for ECOFF and/or
ELF, and since they only want a.out for now (execpt the mips archs, but
they do Special things). There should be a better way to select which
bits of nlist code get compiled in, but currently there is not.

Seriously revamp libc's nlist()/__fdnlist() support:
(1) split nlist() into multiple files, for clarity and to make
ELF 32/64 support easier,
(2) support multiple executable types at the same time, and
(3) add support for 32- and 64-bit ELF (32-bit ELF support
originally from OpenBSD, but with several bug fixes so
that it actually handles symbols types more correctly
(and therefore _works_ for some of the more tricky uses
of the nlist routines) and changes for 64-bit ELF support).