SYSTEM_OBS. They are now normal objects.
Remove stale dependencies for the above now-normal objects and for
locore.o and generate dependencies using mkdep. Config doesn't
generate lists of assembler source files so the lists to be mkdep'ed
have to be given explictly. Only the standard *.s files are given,
so the dependencies for gnu/fpemul/*.s are incomplete. *.S files
would be handled right if config put them in CFILES.
Don't define NPX. It was replaced by NNPX > 0 years ago.
Define LOAD_ADDRESS in COPTS so that compiling machdep.c isn't a special
case.
Moving around the dependencies exposed a bug in make. It doesn't
know that assym.s and ./assym.s are the same. Add a rule tell it.