rtemsbsd: Made TTCP command build for RTEMS

Updated ttcp.c to build clean for RTEMS 6 and the machines it
originally built for. Also fixed ttcp.c to close network
sockets after completion. Defined a shell command for TTCP in
rtems-bsd-shell-ttcp.c. Added TTCP to the list of RTEMS network
commands in netcmds-config.h. Added declaration of the TTCP shell
command to rtems-bsd-commands.h. Modified libbsd.py to make waf
build TTCP and its shell command.

rtemsbsd/rtems/rtems-bsd-shell-ttcp.c

@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/*
+ * COPYRIGHT (c) 2021. On-Line Applications Research Corporation (OAR).
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <rtems/netcmds-config.h>
+#include <machine/rtems-bsd-commands.h>
+
+rtems_shell_cmd_t rtems_shell_TTCP_Command = {
+  "ttcp",                                           /* name */
+  "ttcp -h                     # to get help",      /* usage */
+  "net",                                            /* topic */
+  rtems_shell_main_ttcp,                            /* command */
+  NULL,                                             /* alias */
+  NULL                                              /* next */
+};