patch 9.1.1391: Vim does not have a vertical tabpanel

Problem:  Vim does not have a tabpanel
Solution: include the tabpanel feature
          (Naruhiko Nishino, thinca)

closes: #17263

Co-authored-by: thinca <thinca@gmail.com>
Signed-off-by: Naruhiko Nishino <naru123456789@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/globals.h b/src/globals.h
index 7006364..f143c8f 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -1056,6 +1056,10 @@
 EXTERN tabpage_T    *lastused_tabpage;
 EXTERN int	    redraw_tabline INIT(= FALSE);  // need to redraw tabline
 
+#if defined(FEAT_TABPANEL)
+EXTERN int	    redraw_tabpanel INIT(= FALSE);  // need to redraw tabpanel
+#endif
+
 /*
  * All buffers are linked in a list. 'firstbuf' points to the first entry,
  * 'lastbuf' to the last entry and 'curbuf' to the currently active buffer.