Consistently pass 0 as first and ignored argument to sigprocmask in the
setjmp implementations.

NFCI.

avoid array-bounds issues by using more complete types.

also, don't cast to a type that includes an extra, unused, member.

while here, replace the hard coded offsets in setjmp.S and some
asserts in longjmp.c with assym.h and shared structures for all
the movings parts, and asserts based upon those structures.

avoids GCC 12 warnings.

Save a few global registers during set/longjmp - at least the application
registers and the only currently used system register (%g7).
Sparc now passes the setjmp tests (and should be able to build perl again).

In handwritten asm use -fPIC code instead of -fpic, our libc has grown
large enough for GOT to be larger than 8k.

While here kill redundant PIC ifdefs in setjmp.S - sparc "call"
instruction is piccy by itself.

Tested by martin@

branches: 1.10.4;
Use CCFSZ instead of 96 for standard save operations.

branches: 1.9.4;
Switch sparc to the new compat code layout.

Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22280, verified by myself.

Make the sparc work again; some work from jason, some from me.

Change immediate label references to _C_LABEL().

Quick fix to repair runtime link problem with libc - "SYS_sigaltstack
undefined". The sigaltstack structure layout didn't actually change on
the sparc, so just change the syscall name. A better fix would probably
be to replace the direct system call with a function call to the libc
sigaltstack().

RCSID fixes: Always use the NetBSD rcsid and the macro RCSID() defined in
<machine/asm.h>; Also syscalls should be protected using the SYSLIBC_SCCS
define not LIBC_SCCS

sigaltstack

Use sigstack() in stead of sigaltstack() until we have a sigaltstack()
in the kernel.

make an arch directory in libc, and move all machine dirs into it