Handle old <arpa/nameser.h> with old API

Define the types and classes we use from the new API.

bin/tests/system/rpz/testlib/test-data.h

@@ -31,6 +31,22 @@
 #define LIBRPZ_LIB_OPEN 2
 #include <dns/librpz.h>
 
+#if __NAMESER < 19991006
+/*
+ * If the new API is not available define the values we use.
+ */
+
+#define ns_c_in 1
+
+#define ns_t_invalid 0
+#define ns_t_a	     1
+#define ns_t_cname   5
+#define ns_t_txt     16
+#define ns_t_aaaa    28
+#define ns_t_dname   39
+
+#endif
+
 #include "trpz.h"
 
 #define NODE_FLAG_IPV6_ADDRESS 0x1