patch 9.0.2160: instanceof() should use varargs as second arg

Problem:  instanceof() should use varargs as second arg
Solution: Modify `instanceof()` to use varargs instead of list

Modify `instanceof()` to use varargs instead of list
Valid `instanceof()` arguments are `type`s. A `type` is not a value;
it cannot be added to a list.

This change is non-compatible with the current usage of instanceof;
but instanceof is relatively new and it's a trivial change.

fixes: #13421
closes: #13644

Signed-off-by: Ernie Rael <errael@raelity.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/proto/typval.pro b/src/proto/typval.pro
index 3f577ad..c9845e0 100644
--- a/src/proto/typval.pro
+++ b/src/proto/typval.pro
@@ -53,7 +53,7 @@
 int check_for_opt_buffer_or_dict_arg(typval_T *args, int idx);
 int check_for_object_arg(typval_T *args, int idx);
 int tv_class_alias(typval_T *tv);
-int check_for_class_or_list_arg(typval_T *args, int idx);
+int check_for_class_or_typealias_args(typval_T *args, int idx);
 char_u *tv_get_string(typval_T *varp);
 char_u *tv_get_string_strict(typval_T *varp);
 char_u *tv_get_string_buf(typval_T *varp, char_u *buf);