patch 8.2.2208: Vim9: after reloading a script variable index may be invalid

Problem:    Vim9: after reloading a script variable index may be invalid.
Solution:   When the sequence number doesn't match give an error for using a
            script-local variable from a compiled function. (closes #7547)
diff --git a/src/errors.h b/src/errors.h
index a74da2c..4f404b5 100644
--- a/src/errors.h
+++ b/src/errors.h
@@ -327,3 +327,5 @@
 	INIT(= N_("E1147: List not set"));
 EXTERN char e_cannot_index_str[]
 	INIT(= N_("E1148: Cannot index a %s"));
+EXTERN char e_script_variable_invalid_after_reload_in_function_str[]
+	INIT(= N_("E1149: Script variable is invalid after reload in function %s"));