patch 9.1.0572: cannot specify tab page closing behaviour

Problem:  cannot specify tab page closing behaviour
          (Gianluca Pacchiella)
Solution: Add the 'tabclose' option (LemonBoy).

fixes: #5967
closes: #15204

Signed-off-by: LemonBoy <thatlemon@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/optiondefs.h b/src/optiondefs.h
index 617f3ce..bf3ed35 100644
--- a/src/optiondefs.h
+++ b/src/optiondefs.h
@@ -2462,6 +2462,9 @@
 			    {(char_u *)0L, (char_u *)0L}
 #endif
 			    SCTX_INIT},
+    {"tabclose",    "tcl",  P_STRING|P_VI_DEF|P_ONECOMMA|P_NODUP,
+			    (char_u *)&p_tcl, PV_NONE, did_set_tabclose, expand_set_tabclose,
+			    {(char_u *)"", (char_u *)0L} SCTX_INIT},
     {"tabline",	    "tal",  P_STRING|P_VI_DEF|P_RALL|P_MLE,
 #ifdef FEAT_STL_OPT
 			    (char_u *)&p_tal, PV_NONE, did_set_tabline, NULL,