patch 8.1.2192: cannot easily fill the info popup asynchronously

Problem:    Cannot easily fill the info popup asynchronously.
Solution:   Add the "popuphidden" value to 'completeopt'. (closes #4924)
diff --git a/src/popupwin.c b/src/popupwin.c
index f9c127a..95435f8 100644
--- a/src/popupwin.c
+++ b/src/popupwin.c
@@ -2225,7 +2225,7 @@
 	popup_close_and_callback(wp, &argvars[1]);
 }
 
-    static void
+    void
 popup_hide(win_T *wp)
 {
     if ((wp->w_popup_flags & POPF_HIDDEN) == 0)
@@ -2272,7 +2272,11 @@
     win_T	*wp = find_popup_win(id);
 
     if (wp != NULL)
+    {
 	popup_show(wp);
+	if (wp->w_popup_flags & POPF_INFO)
+	    pum_position_info_popup(wp);
+    }
 }
 
 /*