change xchar to other typedefs

One of the drivers of this change was that screen coordinates require a
type that can hold values greater than 127. Parameters to the window
port routines require a large type in order to be able to have values
a fair bit larger than COLNO and ROWNO passed to them, particularly for
their use to the right of the map window.

This splits the uses of xchar into 3 different situations, and adjusts
their type and size:

                        xchar
                          |
               -----------------------
               |          |          |
            coordxy     xint16     xint8

coordxy: Actual x or y coordinates for various things (moved to 16-bits).

xint16:  Same data size as coordxy, but for non-coordinate use (16-bits).

xint8:   There are only a few use cases initially, where it was very
         plain to see that the variable could remain as 8-bits, rather
         than be bumped to 16-bits.  There are probably more such cases
         that could be changed after additional review.

Note: This first changed all xchar variables to coordxy. Some were
reviewed and got changed to xint16 or xint8 when it became apparent that
their usage was not for coordinates.

This increments EDITLEVEL in patchlevel.h

src/mon.c

@@ -19,7 +19,7 @@ static void mon_leaving_level(struct monst *);
 static void m_detach(struct monst *, struct permonst *);
 static void set_mon_min_mhpmax(struct monst *, int);
 static void lifesaved_monster(struct monst *);
-static void migrate_mon(struct monst *, xchar, xchar);
+static void migrate_mon(struct monst *, coordxy, coordxy);
 static boolean ok_to_obliterate(struct monst *);
 static void deal_with_overcrowding(struct monst *);
 static void m_restartcham(struct monst *);
@@ -1807,7 +1807,7 @@ mfndpos(
 {
     struct permonst *mdat = mon->data;
     register struct trap *ttmp;
-    xchar x, y, nx, ny;
+    coordxy x, y, nx, ny;
     int cnt = 0;
     uchar ntyp;
     uchar nowtyp;
@@ -2357,7 +2357,7 @@ m_detach(
     struct monst *mtmp,
     struct permonst *mptr) /* reflects mtmp->data _prior_ to mtmp's death */
 {
-    xchar mx = mtmp->mx, my = mtmp->my;
+    coordxy mx = mtmp->mx, my = mtmp->my;
 
     if (mtmp->mleashed)
         m_unleash(mtmp, FALSE);
@@ -2790,7 +2790,7 @@ void
 monstone(struct monst* mdef)
 {
     struct obj *otmp, *obj, *oldminvent;
-    xchar x = mdef->mx, y = mdef->my;
+    coordxy x = mdef->mx, y = mdef->my;
     boolean wasinside = FALSE;
 
     /* vampshifter reverts to vampire;
@@ -3284,14 +3284,14 @@ vamp_stone(struct monst *mtmp)
 void
 m_into_limbo(struct monst *mtmp)
 {
-    xchar target_lev = ledger_no(&u.uz), xyloc = MIGR_APPROX_XY;
+    xint16 target_lev = ledger_no(&u.uz), xyloc = MIGR_APPROX_XY;
 
     mtmp->mstate |= MON_LIMBO;
     migrate_mon(mtmp, target_lev, xyloc);
 }
 
 static void
-migrate_mon(struct monst *mtmp, xchar target_lev, xchar xyloc)
+migrate_mon(struct monst *mtmp, xint16 target_lev, xint16 xyloc)
 {
     if (!mtmp->mx) {
         /* this was a failed arrival attempt from a prior migration;
@@ -3382,7 +3382,7 @@ elemental_clog(struct monst *mon)
         /* last resort - migrate mon to the next plane */
         } else if (!Is_astralevel(&u.uz)) {
             d_level dest;
-            xchar target_lev;
+            coordxy target_lev;
 
             dest = u.uz;
             dest.dlevel--;
@@ -3462,13 +3462,13 @@ maybe_mnexto(struct monst* mtmp)
 int
 mnearto(
     register struct monst *mtmp,
-    xchar x,
-    xchar y,
+    coordxy x,
+    coordxy y,
     boolean move_other, /* make sure mtmp gets to x, y! so move m_at(x, y) */
     unsigned int rlocflags)
 {
     struct monst *othermon = (struct monst *) 0;
-    xchar newx, newy;
+    coordxy newx, newy;
     coord mm;
     int res = 1;
 
@@ -3874,8 +3874,8 @@ get_iter_mons(boolean (*func)(struct monst *))
    passing x,y to the function.
    if func returns TRUE, stop and return that monster. */
 struct monst *
-get_iter_mons_xy(boolean (*func)(struct monst *, xchar, xchar),
-                xchar x, xchar y)
+get_iter_mons_xy(boolean (*func)(struct monst *, coordxy, coordxy),
+                coordxy x, coordxy y)
 {
     struct monst *mtmp;
 
@@ -3960,7 +3960,7 @@ restrap(struct monst *mtmp)
 /* reveal a monster at x,y hiding under an object,
    if there are no objects there */
 void
-maybe_unhide_at(xchar x, xchar y)
+maybe_unhide_at(coordxy x, coordxy y)
 {
     struct monst *mtmp;
 
@@ -3978,7 +3978,7 @@ hideunder(struct monst *mtmp)
 {
     struct trap *t;
     boolean oldundetctd, undetected = FALSE, is_u = (mtmp == &g.youmonst);
-    xchar x = is_u ? u.ux : mtmp->mx, y = is_u ? u.uy : mtmp->my;
+    coordxy x = is_u ? u.ux : mtmp->mx, y = is_u ? u.uy : mtmp->my;
 
     if (mtmp == u.ustuck) {
         ; /* can't hide if holding you or held by you */
@@ -4021,7 +4021,7 @@ hide_monst(struct monst* mon)
 
     if ((is_hider(mon->data) || hider_under)
         && !(mon->mundetected || M_AP_TYPE(mon))) {
-        xchar x = mon->mx, y = mon->my;
+        coordxy x = mon->mx, y = mon->my;
         char save_viz = g.viz_array[y][x];
 
         /* override vision, forcing hero to be unable to see monster's spot */
@@ -4541,7 +4541,7 @@ newcham(
         *p = '\0';
 
     if (mtmp->wormno) { /* throw tail away */
-        xchar mx = mtmp->mx, my = mtmp->my;
+        coordxy mx = mtmp->mx, my = mtmp->my;
 
         wormgone(mtmp); /* discards tail segments, takes head off the map */
         /* put the head back; it will morph into mtmp's new form */