joinpath, except that a second or later argument that is
an absolute path will overwrite the previously-merged path. E.g.:
joinpathabsolute('one', 'two', '/three/four', 'five')
Under Windows, partially absolute path arguments - e.g. "/dir" or "C:dir" where the drive or dir is still relative - are considered absolute for the sake of overwriting the merge.
Added in version 7.00.1352770000 20121112. Redundant path separators internal to an argument are not removed, nor are "." and ".." path components removed. Prior to version 7.07.1550082000 20190213 partially absolute arguments were not considered absolute.