[PATCH v5 2/2] io: Use gnulib fts implementation (BZ 22944, BZ 20331)

[Florian Weimer]

* Collin Funk:

> This optimization is quite important. For example, 'chown' and 'chmod'
> do not need to stat the files that they are processing. Using the
> information from stat in those programs would likely introduce some
> nasty TOCTOU races. Therefore, there is no need to do all this extra
> work that glibc does:

This makes sense.

Still I think we need to version the symbol, with an internal flag that
does more stat'ing with FTS_NOSTAT.  If we find problems pretty much
immediately after updating glibc, it tends to suggest fairly widespread
impact.

Thanks,
Florian