patch 8.2.4071: Vim9: no detection of return in try/endtry

Problem:    Vim9: no detection of return in try/endtry. (Dominique Pellé)
Solution:   Check if any of the blocks inside try/endtry did not end in
            return.

src/vim9.h

@@ -594,6 +594,8 @@ typedef struct {
     endlabel_T	*ts_end_label;	    // jump to :finally or :endtry
     int		ts_catch_label;	    // instruction idx of last CATCH
     int		ts_caught_all;	    // "catch" without argument encountered
+    int		ts_has_finally;	    // "finally" encountered
+    int		ts_no_return;	    // one of the blocks did not end in return
 } tryscope_T;
 
 typedef enum {