ia64: Include compat13 sigprocmask and sigsuspend stubs.

All the other ports already do this. Although ia64 was imported long
after 1.4, the same is true of other ports that nevertheless include
these stubs, like amd64.

We could invent a new __NetBSD_Compat_Min__ macro like
__NetBSD_Version__ that tells the earliest version of NetBSD for
which we aim to support compat binaries, and use that to
conditionalize tests like t_compat_cancel.c. But that's a bit more
trouble for something we can dispense with by a couple tiny syscall
stubs.

Should fix build for:

PR lib/59240: POSIX.1-2024: cancellation point audit
PR lib/59247: pthread_cancelstub.c is inadequately tested

branches: 1.3.28;
various ia64 updates:
- add a compat vfork because of stupid
- add a weak sbrk
- add a shmat syscall
- add an empty kvm implementation that links
- add missing fp stuff

merge the bouyer-quota2 branch. This adds a new on-disk format
to store disk quota usage and limits, integrated with ffs
metadata. Usage is checked by fsck_ffs (no more quotacheck)
and is covered by the WAPBL journal. Enabled with kernel
option QUOTA2 (added where QUOTA was enabled in kernel config files),
turned on with tunefs(8) on a per-filesystem
basis. mount_mfs(8) can also turn quotas on.

See http://mail-index.netbsd.org/tech-kern/2011/02/19/msg010025.html
for details.

branches: 1.1.38;
Further ia64 libc compat bits