This reverts https://mail-index.NetBSD.org/source-changes/2019/08/27/msg108499.html which broke the tree on case-insensitive file systems. See discussion at https://mail-index.NetBSD.org/source-changes-d/2019/08/27/msg011590.html for alternatives considered. This does _not_ simply mark the new files as `obsolete' in the set lists, because if we marked foo.bin obsolete then on a case- insensitive file system, then it would try to delete the FOO.bin that we still want installed. We'll require a manual change announced in UPDATING and on current-users. ok msaitoh
