patch 9.1.1531: confusing error with nested legacy function

Problem:  confusing error with nested legacy function
          (lacygoill)
Solution: clarify error message E1117 with :def or :func (Hirohito Higashi)

fixes: #17697
closes: #17702

Signed-off-by: Hirohito Higashi <h.east.727@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/vim9compile.c b/src/vim9compile.c
index 131bab7..a7c412e 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -1035,7 +1035,8 @@
 
     if (eap->forceit)
     {
-	emsg(_(e_cannot_use_bang_with_nested_def));
+	semsg(_(e_cannot_use_bang_with_nested_def_str),
+		eap->cmdidx == CMD_def ? ":def" : ":function");
 	return NULL;
     }