patch 8.2.0149: maintaining a Vim9 branch separately is more work

Problem:    Maintaining a Vim9 branch separately is more work.
Solution:   Merge the Vim9 script changes.
diff --git a/src/proto/ex_eval.pro b/src/proto/ex_eval.pro
index bd68eea..929f479 100644
--- a/src/proto/ex_eval.pro
+++ b/src/proto/ex_eval.pro
@@ -8,7 +8,9 @@
 void do_errthrow(cstack_T *cstack, char_u *cmdname);
 int do_intthrow(cstack_T *cstack);
 char *get_exception_string(void *value, except_type_T type, char_u *cmdname, int *should_free);
+int throw_exception(void *value, except_type_T type, char_u *cmdname);
 void discard_current_exception(void);
+void catch_exception(except_T *excp);
 void report_make_pending(int pending, void *value);
 void ex_eval(exarg_T *eap);
 void ex_if(exarg_T *eap);