alternative to display_inventory for window-port

Several window ports that support perm_invent were
using a call back to the core display_inventory()
function.

While calling from the window port back to core functions
is arguably not ideal in the first place, it was recently
brought to light that code NetHack-3.7 code changes to
display_inventory() actually caused it to stop repopulating
the perm_invent window as intended under certain circumstances.

For now, provide an alternative function, repopulate_perminvent(),
that hopefullshould still work the way it did previously.

There will likely be some additional changes after this to
further improve things, at some point.

For now though, this
Resolves #1454

win/win32/mswproc.c

@@ -1248,7 +1248,7 @@ mswin_select_menu(winid wid, int how, MENU_ITEM_P **selected)
 
 /*
     -- Indicate to the window port that the inventory has been changed.
-    -- Merely calls display_inventory() for window-ports that leave the
+    -- Merely calls repopulate_perminvent() for window-ports that leave the
         window up, otherwise empty.
 */
 void
@@ -1257,7 +1257,7 @@ mswin_update_inventory(int arg)
     logDebug("mswin_update_inventory(%d)\n", arg);
     if (iflags.perm_invent && program_state.something_worth_saving
         && iflags.window_inited && WIN_INVEN != WIN_ERR)
-        display_inventory(NULL, FALSE);
+        repopulate_perminvent();
 }
 
 win_request_info *