linux: move a shared part of sys/ptrace.h to bits/ptrace-shared.h

Move a shared part of sys/ptrace.h which is the same on all
architectures to a separate file.

* sysdeps/unix/sysv/linux/sys/ptrace.h: Include <bits/ptrace-shared.h>.
(__ptrace_setoptions, __ptrace_eventcodes, __ptrace_peeksiginfo_args,
__ptrace_peeksiginfo_flags, ptrace): Move to ...
* sysdeps/unix/sysv/linux/bits/ptrace-shared.h: ... new file.
* sysdeps/unix/sysv/linux/Makefile (sysdep_headers): Add
bits/ptrace-shared.h.
* sysdeps/unix/sysv/linux/aarch64/sys/ptrace.h: Include
<bits/ptrace-shared.h>.
(__ptrace_setoptions, __ptrace_eventcodes, __ptrace_peeksiginfo_args,
__ptrace_peeksiginfo_flags, ptrace): Remove.
* sysdeps/unix/sysv/linux/ia64/sys/ptrace.h: Likewise.
* sysdeps/unix/sysv/linux/powerpc/sys/ptrace.h: Likewise.
* sysdeps/unix/sysv/linux/s390/sys/ptrace.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/sys/ptrace.h: Likewise.
* sysdeps/unix/sysv/linux/tile/sys/ptrace.h: Likewise.