DragonFlyBSD

If cpdup fails to remove an ordinary file, it will try clearing file flags and attempt to remove it again. However, cpdup doesn't currently do that for directories.

Steps to reproduce:
dfly46# mkdir src dst
dfly46# mkdir dst/dir
dfly46# touch dst/file
dfly46# chflags schg dst/dir dst/file
dfly46# cpdup src dst
remove dst/dir (Yes/No) [No]? y
remove dst/file (Yes/No) [No]? y
dst/dir rmdir failed: Operation not permitted