[PATCH] unistd: use __USE_XOPEN2K24 for existing POSIX.1-2024 interfaces

[Florian Weimer]

* Collin Funk:

> diff --git a/conform/data/unistd.h-data b/conform/data/unistd.h-data
> index b4531868fd..15bff17be5 100644
> --- a/conform/data/unistd.h-data
> +++ b/conform/data/unistd.h-data

> +#ifdef POSIX24
> +function int _Fork (void)
> +#endif

That should be:

function pid_t _Fork (void)

I believe.

> +#ifdef POSIX24
> +function int getentropy (void*, size_t)
> +#endif

Surprisingly, this is correct—I would have expected ssize_t as the
return type.

Rest looks okay.  I didn't check if the changes are complete, but at
least what changed matches Issue 8.

Thanks,
Florian