* sysdeps/gnu/bits/msq.h: Qualify kernel's
data structure pointers as __unbounded.
* sysdeps/unix/sysv/linux/mips/bits/shm.h: Likewise.
* sysdeps/generic/bp-semctl.h: New file.
* sysdeps/unix/sysv/linux/msgctl.c: Qualify kernel's data structure
pointers as __unbounded. Check bounds of syscall args.
* sysdeps/unix/sysv/linux/msgrcv.c: Likewise.
* sysdeps/unix/sysv/linux/msgsnd.c: Likewise.
* sysdeps/unix/sysv/linux/semctl.c: Likewise.
* sysdeps/unix/sysv/linux/semop.c: Likewise.
* sysdeps/unix/sysv/linux/shmat.c: Likewise.
* sysdeps/unix/sysv/linux/shmctl.c: Likewise.
* sysdeps/unix/sysv/linux/shmdt.c: Likewise.
* sysdeps/unix/sysv/linux/alpha/msgctl.c: Likewise.
* sysdeps/unix/sysv/linux/alpha/semctl.c: Likewise.
* sysdeps/unix/sysv/linux/alpha/shmctl.c: Likewise.
* sysdeps/unix/sysv/linux/i386/msgctl.c: Likewise.
* sysdeps/unix/sysv/linux/i386/semctl.c: Likewise.
* sysdeps/unix/sysv/linux/i386/shmctl.c: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/msgctl.c: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/semctl.c: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/shmctl.c: Likewise.