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/monmove.c

@@ -12,8 +12,8 @@ static int disturb(struct monst *);
 static void release_hero(struct monst *);
 static void distfleeck(struct monst *, int *, int *, int *);
 static int m_arrival(struct monst *);
-static boolean holds_up_web(xchar, xchar);
-static int count_webbing_walls(xchar, xchar);
+static boolean holds_up_web(coordxy, coordxy);
+static int count_webbing_walls(coordxy, coordxy);
 static boolean soko_allow_web(struct monst *);
 static boolean leppie_avoidance(struct monst *);
 static void leppie_stash(struct monst *);
@@ -812,8 +812,8 @@ should_displace(
     coord *poss, /* coord poss[9] */
     long *info,  /* long info[9] */
     int cnt,
-    xchar gx,
-    xchar gy)
+    coordxy gx,
+    coordxy gy)
 {
     int shortest_with_displacing = -1;
     int shortest_without_displacing = -1;
@@ -845,7 +845,7 @@ should_displace(
 }
 
 boolean
-m_digweapon_check(struct monst* mtmp, xchar nix, xchar niy)
+m_digweapon_check(struct monst* mtmp, coordxy nix, coordxy niy)
 {
     boolean can_tunnel = 0;
     struct obj *mw_tmp = MON_WEP(mtmp);
@@ -940,7 +940,7 @@ m_balks_at_approaching(struct monst* mtmp)
 }
 
 static boolean
-holds_up_web(xchar x, xchar y)
+holds_up_web(coordxy x, coordxy y)
 {
     stairway *sway;
 
@@ -957,7 +957,7 @@ holds_up_web(xchar x, xchar y)
 /* returns the number of walls in the four cardinal directions that could
    hold up a web */
 static int
-count_webbing_walls(xchar x, xchar y)
+count_webbing_walls(coordxy x, coordxy y)
 {
     return (holds_up_web(x, y - 1) + holds_up_web(x + 1, y)
             + holds_up_web(x, y + 1) + holds_up_web(x - 1, y));
@@ -1018,7 +1018,8 @@ int
 m_move(register struct monst* mtmp, register int after)
 {
     int appr, etmp;
-    xchar gx, gy, nix, niy, chcnt;
+    coordxy gx, gy, nix, niy;
+    xint16 chcnt;
     int chi; /* could be schar except for stupid Sun-2 compiler */
     boolean likegold = 0, likegems = 0, likeobjs = 0, likemagic = 0,
             conceals = 0;
@@ -1076,7 +1077,7 @@ m_move(register struct monst* mtmp, register int after)
 
     /* and the acquisitive monsters get special treatment */
     if (is_covetous(ptr)) {
-        xchar tx = STRAT_GOALX(mtmp->mstrategy),
+        coordxy tx = STRAT_GOALX(mtmp->mstrategy),
               ty = STRAT_GOALY(mtmp->mstrategy);
         struct monst *intruder = m_at(tx, ty);
         /*
@@ -1723,7 +1724,7 @@ m_move(register struct monst* mtmp, register int after)
  * (mtmp died) or 3 (mtmp made its move).
  */
 int
-m_move_aggress(struct monst* mtmp, xchar x, xchar y)
+m_move_aggress(struct monst* mtmp, coordxy x, coordxy y)
 {
     struct monst *mtmp2;
     int mstatus;
@@ -1855,8 +1856,8 @@ set_apparxy(register struct monst* mtmp)
 boolean
 undesirable_disp(
     struct monst *mtmp, /* barging creature */
-    xchar x,
-    xchar y) /* spot 'mtmp' is considering moving to */
+    coordxy x,
+    coordxy y) /* spot 'mtmp' is considering moving to */
 {
     boolean is_pet = (mtmp && mtmp->mtame && !mtmp->isminion);
     struct trap *trap = t_at(x, y);