MXS-1840 Compile all routers as C++

Minimal changes, only what is needed in order to make it compile.

server/modules/routing/binlogrouter/blr_cache.cc

@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2016 MariaDB Corporation Ab
+ *
+ * Use of this software is governed by the Business Source License included
+ * in the LICENSE.TXT file and at www.mariadb.com/bsl11.
+ *
+ * Change Date: 2020-01-01
+ *
+ * On the date above, in accordance with the Business Source License, use
+ * of this software will be governed by version 2 or later of the General
+ * Public License.
+ */
+
+/**
+ * @file blr_cache.c - binlog router cache, manage the binlog cache
+ *
+ * The binlog router is designed to be used in replication environments to
+ * increase the replication fanout of a master server. It provides a transparant
+ * mechanism to read the binlog entries for multiple slaves while requiring
+ * only a single connection to the actual master to support the slaves.
+ *
+ * The current prototype implement is designed to support MySQL 5.6 and has
+ * a number of limitations. This prototype is merely a proof of concept and
+ * should not be considered production ready.
+ *
+ * @verbatim
+ * Revision History
+ *
+ * Date     Who     Description
+ * 07/04/2014   Mark Riddoch        Initial implementation
+ *
+ * @endverbatim
+ */
+
+#include "blr.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <maxscale/service.h>
+#include <maxscale/server.h>
+#include <maxscale/router.h>
+#include <maxscale/atomic.h>
+#include <maxscale/spinlock.h>
+#include <maxscale/dcb.h>
+#include <maxscale/spinlock.h>
+
+#include <maxscale/log_manager.h>
+
+
+/**
+ * Initialise the cache for this instanceof the binlog router. As a side
+ * effect also determine the binlog file to read and the position to read
+ * from.
+ *
+ * @param   router      The router instance
+ */
+void
+blr_init_cache(ROUTER_INSTANCE *router)
+{
+}