7006576: (zipfs) Path.exists() always returns false on dirs when zip/JAR file built without dirs

7009092: (zipfs) ZipPath.isSameFile() should always return true if this Path and the given Path are equal
7009085: (zipfs) ZipPath.normalize("/./.") returns null
7009102: (zipfs) ZipPath.toRealPath() should always return absolute path

Zip filesystem provider update

Reviewed-by: alanb