patch 8.1.1773: the preview popup window may be too far to the right
Problem: The preview popup window may be too far to the right.
Solution: Keep it inside the screen. Also keep the close button and
scrollbar visible if possible.
diff --git a/src/proto/popupwin.pro b/src/proto/popupwin.pro
index 04825cc..0a5db0c 100644
--- a/src/proto/popupwin.pro
+++ b/src/proto/popupwin.pro
@@ -9,7 +9,7 @@
int popup_width(win_T *wp);
void popup_adjust_position(win_T *wp);
int parse_previewpopup(win_T *wp);
-void popup_set_wantpos(win_T *wp);
+void popup_set_wantpos(win_T *wp, int width);
void f_popup_clear(typval_T *argvars, typval_T *rettv);
void f_popup_create(typval_T *argvars, typval_T *rettv);
void f_popup_atcursor(typval_T *argvars, typval_T *rettv);