Add unit test for Path.toNativeString() w.r.t. endsWithSlash() and fix Path().toNativeString() on Posix.
Add unit test for Path.toNativeString() w.r.t. endsWithSlash() and fix Path().toNativeString() on Posix.

Flamaros/dub,jelmansouri/dub,p0nce/dub,y12uc231/dub,alexeibs/dub,Geod24/dub,schuetzm/dub,nazriel/dub,grogancolin/dub,rjframe/dub,D-Programming-Language/dub,gedaiu/dub,xentec/dub,Abscissa/dub,jeanbaptistelab/dub,dreamsxin/dub,Abscissa/dub-data-mod