patch 8.2.2652: Vim9: can use command modifier without an effect

Problem:    Vim9: can use command modifier without an effect.
Solution:   Give an error for a misplaced command modifier.  Fix error message
            number.
diff --git a/src/proto/ex_docmd.pro b/src/proto/ex_docmd.pro
index 9ac8eaf..8481063 100644
--- a/src/proto/ex_docmd.pro
+++ b/src/proto/ex_docmd.pro
@@ -8,6 +8,8 @@
 char_u *getline_peek(char_u *(*fgetline)(int, void *, int, getline_opt_T), void *cookie);
 char *ex_errmsg(char *msg, char_u *arg);
 int parse_command_modifiers(exarg_T *eap, char **errormsg, cmdmod_T *cmod, int skip_only);
+int has_cmdmod(cmdmod_T *cmod);
+int cmdmod_error(void);
 void apply_cmdmod(cmdmod_T *cmod);
 void undo_cmdmod(cmdmod_T *cmod);
 int parse_cmd_address(exarg_T *eap, char **errormsg, int silent);