patch 9.1.0255: Vim9: no indication of script nr in stack trace of classes

Problem:  Vim9: no indication of script nr in stack trace of classes
Solution: Prefix the class name with the script name in the stack trace.
          (Ernie Rael)

fixes: #14376
closes: #14390

Signed-off-by: Ernie Rael <errael@raelity.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/scriptfile.c b/src/scriptfile.c
index 6dc5557..109e13e 100644
--- a/src/scriptfile.c
+++ b/src/scriptfile.c
@@ -215,6 +215,9 @@
 	    if (*class_name != NUL)
 	    {
 		// For class methods prepend "<class name>." to the function name.
+		ga_concat(&ga, (char_u *)"<SNR>");
+		ga.ga_len += vim_snprintf((char *)ga.ga_data + ga.ga_len, 23,
+		       "%d_", entry->es_info.ufunc->uf_script_ctx.sc_sid);
 		ga_concat(&ga, class_name);
 		ga_append(&ga, '.');
 	    }