warp inclusion of netinet6/nd6.h by #ifdef INET6.  (sync with netbsd-current)
warp inclusion of netinet6/nd6.h by #ifdef INET6.  (sync with netbsd-current)

MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame