patch 8.2.2785: Vim9: cannot redirect to local variable

Problem:    Vim9: cannot redirect to local variable.
Solution:   Compile :redir when redirecting to a variable.
diff --git a/src/proto/evalvars.pro b/src/proto/evalvars.pro
index c75f80a..58c1222 100644
--- a/src/proto/evalvars.pro
+++ b/src/proto/evalvars.pro
@@ -71,7 +71,7 @@
 void vars_clear_ext(hashtab_T *ht, int free_val);
 void delete_var(hashtab_T *ht, hashitem_T *hi);
 void set_var(char_u *name, typval_T *tv, int copy);
-void set_var_const(char_u *name, type_T *type, typval_T *tv_arg, int copy, int flags, int var_idx);
+void set_var_const(char_u *name, type_T *type, typval_T *tv_arg, int copy, int flags_arg, int var_idx);
 int var_check_permission(dictitem_T *di, char_u *name);
 int var_check_ro(int flags, char_u *name, int use_gettext);
 int var_check_lock(int flags, char_u *name, int use_gettext);
@@ -82,9 +82,13 @@
 void reset_v_option_vars(void);
 void assert_error(garray_T *gap);
 int var_exists(char_u *var);
+int alloc_redir_lval(void);
+void clear_redir_lval(void);
+void init_redir_ga(void);
 int var_redir_start(char_u *name, int append);
 void var_redir_str(char_u *value, int value_len);
 void var_redir_stop(void);
+char_u *get_clear_redir_ga(void);
 void f_gettabvar(typval_T *argvars, typval_T *rettv);
 void f_gettabwinvar(typval_T *argvars, typval_T *rettv);
 void f_getwinvar(typval_T *argvars, typval_T *rettv);