experiment: Add copyright notice.

Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>

common/openpgp-misc.c

@@ -1,8 +1,24 @@
+/* openpgp-misc.c - miscellaneous functions for OpenPGP
+ * Copyright (C) 2021 g10 Code GmbH
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG 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
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <https://www.gnu.org/licenses/>.
+ */
+
 #include <config.h>
 #include <stdlib.h>
-#include <errno.h>
-#include <ctype.h>
-#include <assert.h>
 
 #include "util.h"
 #include "openpgpdefs.h"