Added license notice to testgen.cc

ai/testgen.cc

@@ -1,3 +1,24 @@
+/*
+ * BSD Carbon --- A simple C/C++ unit testing framework
+ * Copyright (C) 2024 Wasym A. Alonso
+ *
+ * This file is part of Carbon.
+ *
+ * Carbon is free software: you can redistribute it and/or modify
+ * it under the terms of the BSD 3-Clause "New" or "Revised" License
+ * as published by The Regents of the University of California.
+ *
+ * Carbon is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * BSD 3-Clause "New" or "Revised" License for more details.
+ *
+ * You should have received a copy of the BSD 3-Clause "New" or
+ * "Revised" License along with Carbon.
+ * If not, see <https://opensource.org/license/BSD-3-Clause>.
+ */
+
+
 #include <sstream>
 #include <fstream>
 #include <iostream>