patch 8.2.3614: zindex of popup windows not used when redrawing popup menu

Problem:    zindex of popup windows not used when redrawing popup menu.
Solution:   Check the zindex when redrawing the popup menu.  (closes #9129,
            closes #9089)
diff --git a/src/screen.c b/src/screen.c
index 78d7ef7..aee18d8 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -2139,7 +2139,7 @@
 
     // Skip if under the popup menu.
     // Popup windows with zindex higher than POPUPMENU_ZINDEX go on top.
-    if (pum_under_menu(row, col)
+    if (pum_under_menu(row, col, TRUE)
 #ifdef FEAT_PROP_POPUP
 	    && screen_zindex <= POPUPMENU_ZINDEX
 #endif