patch 9.1.0020: Vim9: cannot compile all methods in a class

Problem:  Vim9: cannot compile all methods in a class
Solution: Support compiling all the methods in a class using :defcompile
          (Yegappan Lakshmanan)

closes: #13844

Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/proto/userfunc.pro b/src/proto/userfunc.pro
index e393c04..9bb4616 100644
--- a/src/proto/userfunc.pro
+++ b/src/proto/userfunc.pro
@@ -50,6 +50,7 @@
 ufunc_T *define_function(exarg_T *eap, char_u *name_arg, garray_T *lines_to_free, int class_flags, ocmember_T *obj_members, int obj_member_count);
 void ex_function(exarg_T *eap);
 ufunc_T *find_func_by_name(char_u *name, compiletype_T *compile_type);
+void defcompile_function(ufunc_T *ufunc, class_T *cl);
 void ex_defcompile(exarg_T *eap);
 int eval_fname_script(char_u *p);
 int translated_function_exists(char_u *name, int is_global);