* ntdll.h (STATUS_ACCESS_DENIED): Define.

	* ntdll.h (STATUS_ACCESS_DENIED): Define.
	* syscalls.cc (check_dir_not_empty): New static function.
	(unlink_nt): Move code checking for non-empty dir to check_dir_not_empty
	and call check_dir_not_empty instead.
	(rename): Add fault handler.  Check oldpath and newpath for trailing
	. and .. path components and return EINVAL if so.  Check oldpath
	for being on a vrtual file system.  If renaming a dir fails with
	STATUS_ACCESS_DENIED, check if the target dir is non-empty and return
	ENOTEMPTY if so.