Proposed resolution:
This wording is relative to N4917.
Modify [fs.path.itr] as indicated:
-2- A path::iterator is a constant iterator meeting all the requirements of a bidirectional iterator ([bidirectional.iterators]) except that, for dereferenceable iterators a and b of type path::iterator with a == b, there is no requirement that *a and *b are bound to the same object, and its reference may be path. Its value_type is path.