We realy should fix the issue described in PR 24324.

There is one problem with it though: it changes the const DIR * passed
to telldir to a DIR *, and it changes sturct _dirdesc (which is what DIR
is typedefd to). Posix does not require the telldir argument to be const.

So: would this require a major libc bump, or can we get away with versioning
every function that gets DIR* passed?

Should we re-consider a major libc bump for 4.0?

Martin