revisit some coordxy casts inherited from time of xchar

The ones below marked "left,revisit" might be worthy of code changes

explode.c:removed: arg sx,sy passed to breaks() are coordxy and so are the parameters
invent.c: removed: discover_artifact() parameter is xint16, so change cast to match
mail.c: removed: gv.viz_rmin[] contains coordxy's, and enexto() 2nd param is too
mkmaze.c: removed: x, y are coordxy and so are cc->x, cc->y
mkroom.c: removed: tx, ty are coordxy and so are parameters to occupied()
mplayer.c: left,revisit: x,y declared int, but mk_mplayer() params are coordxy
sp_lev.c 2890: left alone: x,y declared int, but is_ok_location() params coordxy
sp_lev.c 4114: left alone: cast from lua_Integer
sp_lev.c 4123: left alone: cast from lua_Integer
sp_lev.c 4650: left alone: cast from lua_Integer returned from lua_tointeger
sp_lev.c 4765: left alone: cast from int_Integer returned from lua_tointeger
sp_lev.c 4772: left alone: cast from int_Integer returned from get_table_int
teleport.c 366: left alone: cast from int returned from rn2()
timeout.c 2171: left alone: cast from long
vault.c: left,revisit: guardx,guardy declared int, but bestcc fields are coordxy
worm.c 791: left,revisit: wseg.wx, wseg.wy are coordxy, so are nx, ny, but not
                          ox, oy; why are ox, oy needed at all?
worm.c 955: left alone: wx, wy are coordxy, wseg_at() params are int x, int y
zap.c 5061: left alone: cast from long

src/apply.c

@@ -1965,8 +1965,8 @@ display_jump_positions(boolean on_off)
         tmp_at(DISP_BEAM, cmap_to_glyph(S_goodpos));
         for (dx = -4; dx <= 4; dx++)
             for (dy = -4; dy <= 4; dy++) {
-                x = dx + (coordxy) u.ux;
-                y = dy + (coordxy) u.uy;
+                x = dx + u.ux;
+                y = dy + u.uy;
                 if (get_valid_jump_position(x, y) && !u_at(x, y))
                     tmp_at(x, y);
             }

src/explode.c

@@ -807,7 +807,7 @@ scatter(coordxy sx, coordxy sy,  /* location of objects to scatter */
         } else if ((scflags & MAY_DESTROY) != 0
                    && (!rn2(10) || (objects[otmp->otyp].oc_material == GLASS
                                     || otmp->otyp == EGG))) {
-            if (breaks(otmp, (coordxy) sx, (coordxy) sy))
+            if (breaks(otmp, sx, sy))
                 used_up = TRUE;
         }
 

src/invent.c

@@ -2537,7 +2537,7 @@ fully_identify_obj(struct obj *otmp)
 {
     makeknown(otmp->otyp);
     if (otmp->oartifact)
-        discover_artifact((coordxy) otmp->oartifact);
+        discover_artifact((xint16) otmp->oartifact);
     otmp->known = otmp->dknown = otmp->bknown = otmp->rknown = 1;
     set_cknown_lknown(otmp); /* set otmp->{cknown,lknown} if applicable */
     if (otmp->otyp == EGG && otmp->corpsenm != NON_PM)

src/mail.c

@@ -201,7 +201,7 @@ md_start(coord *startp)
                     startp->y = row;
                     startp->x = gv.viz_rmin[row];
 
-                } else if (enexto(&testcc, (coordxy) gv.viz_rmin[row], row,
+                } else if (enexto(&testcc, gv.viz_rmin[row], row,
                                   (struct permonst *) 0)
                            && !cansee(testcc.x, testcc.y)
                            && couldsee(testcc.x, testcc.y)) {
@@ -216,7 +216,7 @@ md_start(coord *startp)
                     startp->y = row;
                     startp->x = gv.viz_rmax[row];
 
-                } else if (enexto(&testcc, (coordxy) gv.viz_rmax[row], row,
+                } else if (enexto(&testcc, gv.viz_rmax[row], row,
                                   (struct permonst *) 0)
                            && !cansee(testcc.x, testcc.y)
                            && couldsee(testcc.x, testcc.y)) {

src/mkmaze.c

@@ -1322,8 +1322,8 @@ mazexy(coord *cc)
         x = rnd(gx.x_maze_max);
         y = rnd(gy.y_maze_max);
         if (levl[x][y].typ == allowedtyp) {
-            cc->x = (coordxy) x;
-            cc->y = (coordxy) y;
+            cc->x = x;
+            cc->y = y;
             return;
         }
     } while (++cpt < 100);
@@ -1331,8 +1331,8 @@ mazexy(coord *cc)
     for (x = 1; x <= gx.x_maze_max; x++)
         for (y = 1; y <= gy.y_maze_max; y++)
             if (levl[x][y].typ == allowedtyp) {
-                cc->x = (coordxy) x;
-                cc->y = (coordxy) y;
+                cc->x = x;
+                cc->y = y;
                 return;
             }
     /* every spot on the area of map allowed for mazes has been rejected */

src/mkroom.c

@@ -293,7 +293,7 @@ fill_zoo(struct mkroom *sroom)
             (void) somexyspace(sroom, &mm);
             tx = mm.x;
             ty = mm.y;
-        } while (occupied((coordxy) tx, (coordxy) ty) && --i > 0);
+        } while (occupied(tx, ty) && --i > 0);
  throne_placed:
         mk_zoo_thronemon(tx, ty);
         break;