This patch refactor the internal sysvipc in two main points:
1. Add a new __ASSUME_SYSVIPC_DEFAULT_IPC_64 to infer the __IPC_64
value to be used along either the multiplexed __NR_ipc or wired-up
syscall. The defaut value assumed for __IPC_64 is also changed
from 0x100 to 0x0, aligning with Linux generic UAPI. The idea
is to simplify the Linux 5.1 wire-up for sysvipc syscalls for
some 32-bit ABIs (which expectes __IPC_64 being 0x0) and simplify
new ports (which will no longer need to add ipc_priv.h).
2. It also removes some duplicated internal definition used on compat
sysvipc symbols defined at ipc_priv.h (more specifically the
__old_ipc_perm, SEMCTL_ARG_ADDRESS, MSGRCV_ARGS, and
SEMTIMEDOP_IPC_ARGS). The idea is also to make it simpler to enable
the new wire-up sysvipc syscall provided by Linux v5.1.
There is no semantic change expected on any port. Checked with a build
against all affected ABIs.
Reviewed-by: Florian Weimer <fweimer@redhat.com>