patch 8.2.4053: Vim9: autoload mechanism doesn't fully work yet

Problem:    Vim9: autoload mechanism doesn't fully work yet.
Solution:   Define functions and variables with their autoload name, add the
            prefix when calling a function, find the variable in the table of
            script variables.
diff --git a/src/proto/scriptfile.pro b/src/proto/scriptfile.pro
index 140d67b..477dc3e 100644
--- a/src/proto/scriptfile.pro
+++ b/src/proto/scriptfile.pro
@@ -38,6 +38,7 @@
 void do_finish(exarg_T *eap, int reanimate);
 int source_finished(char_u *(*fgetline)(int, void *, int, getline_opt_T), void *cookie);
 char_u *script_name_after_autoload(scriptitem_T *si);
+char_u *get_autoload_prefix(scriptitem_T *si);
 char_u *may_prefix_autoload(char_u *name);
 char_u *autoload_name(char_u *name);
 int script_autoload(char_u *name, int reload);
diff --git a/src/proto/vim9script.pro b/src/proto/vim9script.pro
index 2644824..46211dd 100644
--- a/src/proto/vim9script.pro
+++ b/src/proto/vim9script.pro
@@ -13,7 +13,7 @@
 void ex_import(exarg_T *eap);
 int find_exported(int sid, char_u *name, ufunc_T **ufunc, type_T **type, cctx_T *cctx, int verbose);
 char_u *vim9_declare_scriptvar(exarg_T *eap, char_u *arg);
-void update_vim9_script_var(int create, dictitem_T *di, int flags, typval_T *tv, type_T **type, int do_member);
+void update_vim9_script_var(int create, dictitem_T *di, char_u *name, int flags, typval_T *tv, type_T **type, int do_member);
 void hide_script_var(scriptitem_T *si, int idx, int func_defined);
 svar_T *find_typval_in_script(typval_T *dest, scid_T sid);
 int check_script_var_type(svar_T *sv, typval_T *value, char_u *name, where_T where);