[PATCH 1/3] <fd_to_filename.h>: Add type safety and port to Hurd

[Florian Weimer]

* Adhemerval Zanella:

> Do we really such optimization which results in somewhat complicate
> code? Couldn't we use something simple as:
>
> char *
> __fd_to_filename (int descriptor, struct fd_to_filename *storage)
> {
>   char *buf = storage->buffer;
>   int i, j;
>
>   for (i = 0; (buf[i] = FD_TO_FILENAME_PREFIX[i]); i++);
>   if (descriptor == 0)
>     {
>       buf[i] = '0';
>       buf[i+1] = '\0';
>       return storage->buffer;
>     }
>
>   for (j = descriptor; j != 0; j /= 10, i++);
>   buf[i] = '\0';
>   for (; descriptor != 0; descriptor /= 10) 
>     buf[--i] = '0' + descriptor % 10;
>
>   return storage->buffer;
> }

I don't have a strong opinion about this (but I think we should probably
keep the mempcpy).  Most descriptors will be fairly small, so the
smaller code size is probably more important.

Thanks,
Florian