patch 9.0.1254: calling a method on an interface does not work
Problem: Calling a method on an interface does not work.
Solution: At runtime figure out what method to call. (closes #11901)
diff --git a/src/proto/vim9class.pro b/src/proto/vim9class.pro
index 13a643d..707f4ec 100644
--- a/src/proto/vim9class.pro
+++ b/src/proto/vim9class.pro
@@ -1,5 +1,5 @@
/* vim9class.c */
-int object_index_from_itf_index(class_T *itf, int idx, class_T *cl);
+int object_index_from_itf_index(class_T *itf, int is_method, int idx, class_T *cl);
void ex_class(exarg_T *eap);
type_T *class_member_type(class_T *cl, char_u *name, char_u *name_end, int *member_idx);
void ex_enum(exarg_T *eap);