patch 8.2.3657: Vim9: debug text misses one line of return statement

Problem:    Vim9: debug text misses one line of return statement.
Solution:   Add a line when not at a debug instruction. (closes #9137)
diff --git a/src/vim9execute.c b/src/vim9execute.c
index 8a14a85..5593f58 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -1602,7 +1602,7 @@
 		  || ni->isn_type == ISN_RETURN
 		  || ni->isn_type == ISN_RETURN_VOID)
 	{
-	    end_lnum = ni->isn_lnum;
+	    end_lnum = ni->isn_lnum + (ni->isn_type == ISN_DEBUG ? 0 : 1);
 	    break;
 	}