Use reach-over sources from common/lib/libc
Move UCB-licensed code from 4-clause to 3-clause licence.Patches provided by Joel Baker in PR 22280, verified by myself.
RCSID fixes: Always use the NetBSD rcsid and the macro RCSID() defined in<machine/asm.h>; Also syscalls should be protected using the SYSLIBC_SCCSdefine not LIBC_SCCS
Remove DEFS.h, which has been just a placeholder for a long time.
need these now, with new net Makefile.inc
Clean up deleted files.
make an arch directory in libc, and move all machine dirs into it