patch 8.1.1646: build failure

Problem:    build failure
Solution:   Add changes to structure.
diff --git a/src/structs.h b/src/structs.h
index 4c4ce7d..57a09fa 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -2941,6 +2941,9 @@
     linenr_T	w_popup_lnum;	    // close popup if cursor not on this line
     colnr_T	w_popup_mincol;	    // close popup if cursor before this col
     colnr_T	w_popup_maxcol;	    // close popup if cursor after this col
+    int		w_popup_mouse_row;  // close popup if mouse moves away
+    int		w_popup_mouse_mincol;  // close popup if mouse moves away
+    int		w_popup_mouse_maxcol;  // close popup if mouse moves away
     int		w_popup_drag;	    // allow moving the popup with the mouse
     popclose_T	w_popup_close;	    // allow closing the popup with the mouse