patch 9.1.1232: Vim script is missing the tuple data type

Problem:  Vim script is missing the tuple data type
Solution: Add support for the tuple data type
          (Yegappan Lakshmanan)

closes: #16776

Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/dict.c b/src/dict.c
index 7975904..d43ca86 100644
--- a/src/dict.c
+++ b/src/dict.c
@@ -1554,7 +1554,7 @@
 	return;
 
     if ((what == DICT2LIST_ITEMS
-		? check_for_string_or_list_or_dict_arg(argvars, 0)
+		? check_for_string_list_tuple_or_dict_arg(argvars, 0)
 		: check_for_dict_arg(argvars, 0)) == FAIL)
 	return;
 
@@ -1617,6 +1617,8 @@
 	string2items(argvars, rettv);
     else if (argvars[0].v_type == VAR_LIST)
 	list2items(argvars, rettv);
+    else if (argvars[0].v_type == VAR_TUPLE)
+	tuple2items(argvars, rettv);
     else
 	dict2list(argvars, rettv, DICT2LIST_ITEMS);
 }