Clone the directory src to dest in one call. dest must not exist; its parent must. Resolves false where a directory clone isn't possible (anything but APFS), so the caller can fall back to cloneFiles.
src
dest
cloneFiles
Clone the directory
srctodestin one call.destmust not exist; its parent must. Resolves false where a directory clone isn't possible (anything but APFS), so the caller can fall back tocloneFiles.