groundwork for an interface change

Add a new window-port interface function
     perminvent_info *
     update_invent_slot(winid window, int slot, perminvent_info *);

That should be nice and flexible and allow exchanges of useful
information between the core and the window port. Information
to be exchange can be easily modified in include/wintype.h as
things evolve.

Information useful to the core can be exchanged from the
window-port in struct to_core.

Information useful from the core to the window-port can be
passed in struct from_core.

I'm not going to update any docs until much later after things
are fully working and settled.

This also doesn't fix or have anything to do with existing
TTY_PERM_INVENT issues.

win/win32/mswproc.c

@@ -100,7 +100,7 @@ struct window_procs mswin_procs = {
     genl_putmixed, mswin_display_file, mswin_start_menu, mswin_add_menu,
     mswin_end_menu, mswin_select_menu,
     genl_message_menu, /* no need for X-specific handling */
-    mswin_update_inventory, mswin_mark_synch, mswin_wait_synch,
+    mswin_mark_synch, mswin_wait_synch,
 #ifdef CLIPPING
     mswin_cliparound,
 #endif
@@ -119,6 +119,8 @@ struct window_procs mswin_procs = {
     mswin_status_init, mswin_status_finish, mswin_status_enablefield,
     mswin_status_update,
     genl_can_suspend_yes,
+    mswin_update_inventory,
+    mswin_update_invent_slot,
 };
 
 /*
@@ -1241,6 +1243,17 @@ mswin_update_inventory(int arg)
         display_inventory(NULL, FALSE);
 }
 
+perminvent_info *
+mswin_update_invent_slot(
+    winid window,  /* window to use, must be of type NHW_MENU */
+    int inventory_slot,                 /* slot id: 0 - info return to core */
+                                        /*          1 - gold slot */
+                                        /*          2 - 29 obj slots */
+    perminvent_info *pi)
+{
+    return (perminvent_info *) 0;
+}
+
 /*
 mark_synch()    -- Don't go beyond this point in I/O on any channel until
                    all channels are caught up to here.  Can be an empty call

win/win32/winMS.h

@@ -161,7 +161,6 @@ void mswin_add_menu(winid wid, const glyph_info *glyphinfo,
                     const char *str, unsigned int itemflags);
 void mswin_end_menu(winid wid, const char *prompt);
 int mswin_select_menu(winid wid, int how, MENU_ITEM_P **selected);
-void mswin_update_inventory(int);
 void mswin_mark_synch(void);
 void mswin_wait_synch(void);
 void mswin_cliparound(int x, int y);
@@ -193,6 +192,8 @@ void mswin_status_finish(void);
 void mswin_status_enablefield(int fieldidx, const char *nm, const char *fmt,
                               boolean enable);
 void mswin_status_update(int idx, genericptr_t ptr, int chg, int percent, int color, unsigned long *colormasks);
+void mswin_update_inventory(int);
+perminvent_info *mswin_update_invent_slot(winid, int, perminvent_info *);
 
 /* helper function */
 HWND mswin_hwnd_from_winid(winid wid);