if they have a foe but you don't, i.e. if their foe is out of your LOS.
Don't allow patrolling to a target grid that is occupied by a monster in case it's a stationary monster (plant or sleeping).
git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@5311 c06c8d41-db1a-0410-9941-cceddc491573
H7AOW4T4Q7AKOXREMK6ZXN3GK6A4I24ICE6VTROMJ5Y3LX47TSDAC
continue;
// Don't bother moving to squares (currently) occupied by a
// monster. We'll usually be able to find other target squares
// (and if we're not, we couldn't move anyway), and this avoids
// monsters trying to move onto a grid occupied by a plant or
// sleeping monster.
if (mgrd[pos_x][pos_y] != NON_MONSTER)