patch 9.0.1336: functions without arguments are not always declared properly
Problem: Functions without arguments are not always declared properly.
Solution: Use "(void)" instead of "()". (Yegappan Lakshmanan, closes #12031)
diff --git a/src/popupmenu.c b/src/popupmenu.c
index cbb45a5..a28b3e2 100644
--- a/src/popupmenu.c
+++ b/src/popupmenu.c
@@ -387,7 +387,7 @@
* This will avoid clearing and redrawing the popup menu, prevent flicker.
*/
void
-pum_call_update_screen()
+pum_call_update_screen(void)
{
call_update_screen = TRUE;