patch 8.2.4989: cannot specify a function name for :defcompile

Problem:    Cannot specify a function name for :defcompile.
Solution:   Implement a function name argument for :defcompile.
diff --git a/src/proto/userfunc.pro b/src/proto/userfunc.pro
index 7bedac0..5372760 100644
--- a/src/proto/userfunc.pro
+++ b/src/proto/userfunc.pro
@@ -45,6 +45,7 @@
 void list_functions(regmatch_T *regmatch);
 ufunc_T *define_function(exarg_T *eap, char_u *name_arg, garray_T *lines_to_free);
 void ex_function(exarg_T *eap);
+ufunc_T *find_func_by_name(char_u *name, compiletype_T *compile_type);
 void ex_defcompile(exarg_T *eap);
 int eval_fname_script(char_u *p);
 int translated_function_exists(char_u *name, int is_global);