Unify mfndpos monster movement flags

src/mon.c

@@ -1541,6 +1541,65 @@ struct obj *otmp;
     return iquan;
 }
 
+/* return flags based on monster data, for mfndpos() */
+long
+mon_allowflags(mtmp)
+struct monst *mtmp;
+{
+    long flags = 0L;
+    boolean can_open = !(nohands(mtmp->data) || verysmall(mtmp->data));
+    boolean can_unlock = ((can_open && monhaskey(mtmp, TRUE))
+                          || mtmp->iswiz || is_rider(mtmp->data));
+    boolean doorbuster = is_giant(mtmp->data);
+
+    if (mtmp->mtame)
+        flags |= ALLOW_M | ALLOW_TRAPS | ALLOW_SANCT | ALLOW_SSM;
+    else if (mtmp->mpeaceful)
+        flags |= ALLOW_SANCT | ALLOW_SSM;
+    else
+        flags |= ALLOW_U;
+    if (Conflict && !resist(mtmp, RING_CLASS, 0, 0))
+        flags |= ALLOW_U;
+    if (mtmp->isshk)
+        flags |= ALLOW_SSM;
+    if (mtmp->ispriest)
+        flags |= ALLOW_SSM | ALLOW_SANCT;
+    if (passes_walls(mtmp->data))
+        flags |= (ALLOW_ROCK | ALLOW_WALL);
+    if (throws_rocks(mtmp->data))
+        flags |= ALLOW_ROCK;
+    if (tunnels(mtmp->data)
+        && !Is_rogue_level(&u.uz)) /* same restriction as m_move() */
+        flags |= ALLOW_DIG;
+    if (doorbuster)
+        flags |= BUSTDOOR;
+    if (can_open)
+        flags |= OPENDOOR;
+    if (can_unlock)
+        flags |= UNLOCKDOOR;
+    if (passes_bars(mtmp->data))
+        flags |= ALLOW_BARS;
+    if (is_displacer(mtmp->data))
+        flags |= ALLOW_MDISP;
+    if (is_minion(mtmp->data) || is_rider(mtmp->data))
+        flags |= ALLOW_SANCT;
+    /* unicorn may not be able to avoid hero on a noteleport level */
+    if (is_unicorn(mtmp->data) && !noteleport_level(mtmp))
+        flags |= NOTONL;
+    if (passes_walls(mtmp->data))
+        flags |= (ALLOW_WALL | ALLOW_ROCK);
+    if (passes_bars(mtmp->data))
+        flags |= ALLOW_BARS;
+    if (is_human(mtmp->data) || mtmp->data == &mons[PM_MINOTAUR])
+        flags |= ALLOW_SSM;
+    if ((is_undead(mtmp->data) && mtmp->data->mlet != S_GHOST) || is_vampshifter(mtmp))
+        flags |= NOGARLIC;
+    if (throws_rocks(mtmp->data))
+        flags |= ALLOW_ROCK;
+
+    return flags;
+}
+
 /* return number of acceptable neighbour positions */
 int
 mfndpos(mon, poss, info, flag)