Revert "Merge dirEntries unittests and modify to run within the same tes...

...tdir."

This reverts commit 249c6328ff8e8c339851f5d597181d0b803fbc12.

https://github.com/D-Programming-Language/phobos/pull/1657

This is a *test* to see if it triggers a bug in osx64 release.