tests: add function record_count_messages

tests/tests-record.cpp

@@ -204,6 +204,16 @@ record_search (const char *buffer, const char *prefix, const char *message,
     return NULL;
 }
 
+/*
+ * Returns the number of messages displayed during the recording.
+ */
+
+int
+record_count_messages ()
+{
+    return arraylist_size (recorded_messages);
+}
+
 /*
  * Adds all recorded messages to the dynamic string "msg".
  */