[PATCH] io: Use gnulib fts implementation (BZ 22944, BZ 20331)

[Florian Weimer]

* Bruno Haible:

> Florian Weimer wrote:
>> > Like the directory resolv/nss_dns/ under resolv/.
>> > Or like the directories nss/nss_compat/, nss/nss_db/, nss/nss_files/
>> > under nss/.
>> 
>> That requires using vpath.  The glibc build system is not really
>> compatible with that.
>
> What do you mean by that? I see more than 20 uses of 'vpath' in glibc:

We have to use vpath because the build system does not really support
subdirectories.  Unfortunately, vpath is quite expensive in terms of
build time, so it's best to minimize its use.

Thanks,
Florian