vim-patch:8.2.4739: accessing freed memory after WinScrolled autocmd event (#18090)

Problem:    Accessing freed memory after WinScrolled autocmd event.
Solution:   Check the window pointer is still valid. (closes vim/vim#10156)
            Remove the argument from may_trigger_winscrolled().
d58862d18f

src/nvim/normal.c

@@ -1225,7 +1225,7 @@ static void normal_check_window_scrolled(NormalState *s)
 {
   if (!finish_op) {
     // Trigger Scroll if the viewport changed.
-    may_trigger_winscrolled(curwin);
+    may_trigger_winscrolled();
   }
 }