patch 8.1.1421: drawing "~" line in popup window

Problem:    Drawing "~" line in popup window.
Solution:   Just draw text in the last line of the popup window.
diff --git a/src/proto/popupwin.pro b/src/proto/popupwin.pro
index 37b5273..83b5f2c 100644
--- a/src/proto/popupwin.pro
+++ b/src/proto/popupwin.pro
@@ -1,13 +1,14 @@
 /* popupwin.c */
+void popup_adjust_position(win_T *wp);
 void f_popup_create(typval_T *argvars, typval_T *rettv);
 int popup_any_visible(void);
 void f_popup_close(typval_T *argvars, typval_T *rettv);
 void f_popup_hide(typval_T *argvars, typval_T *rettv);
-void f_popup_getposition(typval_T *argvars, typval_T *rettv);
 void f_popup_show(typval_T *argvars, typval_T *rettv);
 void popup_close(int id);
 void popup_close_tabpage(tabpage_T *tp, int id);
 void close_all_popups(void);
 void ex_popupclear(exarg_T *eap);
 void f_popup_move(typval_T *argvars, typval_T *rettv);
+void f_popup_getposition(typval_T *argvars, typval_T *rettv);
 /* vim: set ft=c : */