locitest: generate tests from the test_data files

The "c" section of the test data file should allocate and populate a LOCI
object. The resulting wire buffer is compared to the "binary" section.

This only tests serialization, but given that we have autogenerated tests that
round-trip each object I think this is sufficient.

I added C sections to the OF 1.0 test data files. OF 1.3 tests will come in a
future pull request.
diff --git a/test_data/of10/packet_in.data b/test_data/of10/packet_in.data
index f8d026b..8168e3b 100644
--- a/test_data/of10/packet_in.data
+++ b/test_data/of10/packet_in.data
@@ -16,3 +16,14 @@
     in_port=ofp.OFPP_LOCAL,
     reason=ofp.OFPR_ACTION,
     data='abc')
+-- c
+obj = of_packet_in_new(OF_VERSION_1_0);
+of_packet_in_buffer_id_set(obj, 2882400001);
+{
+    of_octets_t data = { .bytes=3, .data=(uint8_t *)"\x61\x62\x63" };
+    of_packet_in_data_set(obj, &data);
+}
+of_packet_in_in_port_set(obj, 65534);
+of_packet_in_reason_set(obj, 1);
+of_packet_in_total_len_set(obj, 9);
+of_packet_in_xid_set(obj, 305419896);