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/dig.c

@@ -6,7 +6,7 @@
 #include "hack.h"
 
 static boolean rm_waslit(void);
-static void mkcavepos(xchar, xchar, int, boolean, boolean);
+static void mkcavepos(coordxy, coordxy, int, boolean, boolean);
 static void mkcavearea(boolean);
 static int dig(void);
 static void dig_up_grave(coord *);
@@ -28,7 +28,7 @@ enum dig_types {
 static boolean
 rm_waslit(void)
 {
-    register xchar x, y;
+    register coordxy x, y;
 
     if (levl[u.ux][u.uy].typ == ROOM && levl[u.ux][u.uy].waslit)
         return TRUE;
@@ -44,7 +44,7 @@ rm_waslit(void)
  * immediately after the effect is complete.
  */
 static void
-mkcavepos(xchar x, xchar y, int dist, boolean waslit, boolean rockit)
+mkcavepos(coordxy x, coordxy y, int dist, boolean waslit, boolean rockit)
 {
     register struct rm *lev;
 
@@ -87,9 +87,9 @@ static void
 mkcavearea(boolean rockit)
 {
     int dist;
-    xchar xmin = u.ux, xmax = u.ux;
-    xchar ymin = u.uy, ymax = u.uy;
-    register xchar i;
+    coordxy xmin = u.ux, xmax = u.ux;
+    coordxy ymin = u.uy, ymax = u.uy;
+    register coordxy i;
     register boolean waslit = rm_waslit();
 
     if (rockit)
@@ -135,7 +135,7 @@ mkcavearea(boolean rockit)
 
 /* When digging into location <x,y>, what are you actually digging into? */
 int
-dig_typ(struct obj *otmp, xchar x, xchar y)
+dig_typ(struct obj *otmp, coordxy x, coordxy y)
 {
     boolean ispick;
 
@@ -231,7 +231,7 @@ static int
 dig(void)
 {
     struct rm *lev;
-    xchar dpx = g.context.digging.pos.x, dpy = g.context.digging.pos.y;
+    coordxy dpx = g.context.digging.pos.x, dpy = g.context.digging.pos.y;
     boolean ispick = uwep && is_pick(uwep);
     const char *verb = (!uwep || is_pick(uwep)) ? "dig into" : "chop through";
 
@@ -734,7 +734,7 @@ DISABLE_WARNING_FORMAT_NONLITERAL
  * in apply.c.
  */
 void
-liquid_flow(xchar x, xchar y, schar typ, struct trap *ttmp,
+liquid_flow(coordxy x, coordxy y, schar typ, struct trap *ttmp,
             const char *fillmsg)
 {
     struct obj *objchain;
@@ -773,7 +773,7 @@ dighole(boolean pit_only, boolean by_magic, coord *cc)
     struct rm *lev;
     struct obj *boulder_here;
     schar typ, old_typ;
-    xchar dig_x, dig_y;
+    coordxy dig_x, dig_y;
     boolean nohole, retval = FALSE;
 
     if (!cc) {
@@ -901,7 +901,7 @@ static void
 dig_up_grave(coord *cc)
 {
     struct obj *otmp;
-    xchar dig_x, dig_y;
+    coordxy dig_x, dig_y;
 
     if (!cc) {
         dig_x = u.ux;
@@ -1220,7 +1220,7 @@ watchman_canseeu(struct monst *mtmp)
  * zap == TRUE if wand/spell of digging, FALSE otherwise (chewing)
  */
 void
-watch_dig(struct monst *mtmp, xchar x, xchar y, boolean zap)
+watch_dig(struct monst *mtmp, coordxy x, coordxy y, boolean zap)
 {
     struct rm *lev = &levl[x][y];
 
@@ -1985,7 +1985,7 @@ rot_organic(anything *arg, long timeout UNUSED)
 void
 rot_corpse(anything *arg, long timeout)
 {
-    xchar x = 0, y = 0;
+    coordxy x = 0, y = 0;
     struct obj *obj = arg->a_obj;
     boolean on_floor = obj->where == OBJ_FLOOR,
             in_invent = obj->where == OBJ_INVENT;