patch 9.0.1041: cannot define a method in a class

Problem:    Cannot define a method in a class.
Solution:   Implement defining an object method.  Make calling an object
            method work.
diff --git a/src/proto/vim9instr.pro b/src/proto/vim9instr.pro
index 04d7682..d0b0d86 100644
--- a/src/proto/vim9instr.pro
+++ b/src/proto/vim9instr.pro
@@ -4,6 +4,7 @@
 isn_T *generate_instr_type(cctx_T *cctx, isntype_T isn_type, type_T *type);
 isn_T *generate_instr_debug(cctx_T *cctx);
 int generate_CONSTRUCT(cctx_T *cctx, class_T *cl);
+int generate_OBJ_MEMBER(cctx_T *cctx, int idx, type_T *type);
 int may_generate_2STRING(int offset, int tolerant, cctx_T *cctx);
 int generate_add_instr(cctx_T *cctx, vartype_T vartype, type_T *type1, type_T *type2, exprtype_T expr_type);
 vartype_T operator_type(type_T *type1, type_T *type2);