Don't provide these definitions on netbsd as before, but without relying
on int8_t being a macro.

branches: 1.6.52;
Retire varargs.h support. Move machine/stdarg.h logic into MI
sys/stdarg.h and expect compiler to provide proper builtins, defaulting
to the GCC interface. lint still has a special fallback.
Reduce abuse of _BSD_VA_LIST_ by defining __va_list by default and
derive va_list as required by standards.

Fix PR port-atari/40315: Bootloader fails on Atari TT030
Add asm sources which provide a fixed entry point for raw bootxx and bootxxx
because modern aggressive gcc4 may reorder functions in the same source
and the first function in a C source won't always appear at the beginning
in its object.

Also overhaul various files in the stand directory:
- rename stand/Makefile.inc to stand/Makefile.booters and
explicitly include it from each Makefile because the stand
directory contains non standalone programs like installboot and
Makefile.inc will be included implicitly from all Makefiles in SUBDIRs
- put more common options into Makefile.booters so that
all boot programs use proper options (-Os etc.)
- make standalone boot programs compile without installed ${DESTDIR}:
- create machine and m68k symlinks in ${.OBJDIR} in all boot programs
- set appropriate make environments to suppress errors and warnings
- <string.h> isn't there in _STANDALONE case
- put #ifdef TOSTOOLS (looks equivarent with !_STANDALONE)
to some files in stand/tostools
- use ${LD} ${LINKFLAGS} rather than ${CC} ${LDFLAGS}
- create raw binaries on ${PROG} target rather than on beforeinstall
and stop weird renaming on beforeinstall and afterinstall
- print proper error message if bootxx size is larger than limit
- create ${DESTDIR}/usr/mdec/{milan,std} directories on beforeinstall
in all boot programs
(XXX: how can we put MD /usr/mdec/foo directories into src/etc/mtree?)
- prototype warnsfy
- cleanup Makefiles for readablity and remove unnecessary rules
- no need to use daddr_t in installboot because the AHDI label doesn't
support 64 bit block numbers

Tested by David Ross (PR submitter) on port-atari, and
finally NetBSD/atari on TT030 is now fully functional.

Should be pulled up to netbsd-4 (where gcc4 was initially imported)
and netbsd-5.

branches: 1.4.68; 1.4.118; 1.4.122; 1.4.130; 1.4.132;
Move some disk I/O and disklabel functions into the library. The code
mostly originated from aptck. Need an extra pass over aptck to cut out all
functionality now moved to the library...

branches: 1.3.4;
Second pass of the bootloader reworking. Everything works from the
TOS/MiNT side now.

Check-point my work on the bootcode.

branches: 1.1.1;
Initial revision