wrappers for multiplexed syscalls (was Re: glibc at the Toolchains microconference at LPC 2019)

[Florian Weimer]

* Dmitry V. Levin:

> What if we start adding separate functions for new interfaces of already
> existing multiplexed system call wrappers?
>
> For example, ptrace is going to gain a new command (PTRACE_GET_SYSCALL_INFO)
> in Linux 5.3.  My initial plan was just to update sys/ptrace.h with a new
> constant and bits/ptrace-shared.h with a new structure, but I could add
> a new function as well:
>
> extern int ptrace_get_syscall_info (__pid_t __pid,
> 				    struct __ptrace_syscall_info *__infop)
> 	__THROW;

I think this makes a lot of sense.  We should also do this for existing
constants (and for fcntl, too).  Perhaps after we have added more of the
wrappers that are *completely* missing, though.

For futex, it will also help with the time_t transition.

Thanks,
Florian