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/port_mod.data b/test_data/of10/port_mod.data
index 972a4e8..53e09ce 100644
--- a/test_data/of10/port_mod.data
+++ b/test_data/of10/port_mod.data
@@ -16,3 +16,14 @@
     config=0x90ABCDEF,
     mask=0xFF11FF11,
     advertise=0xCAFE6789)
+-- c
+obj = of_port_mod_new(OF_VERSION_1_0);
+of_port_mod_advertise_set(obj, 3405670281);
+of_port_mod_config_set(obj, 2427178479);
+{
+    of_mac_addr_t hw_addr = { { 1, 2, 3, 4, 5, 6 } };
+    of_port_mod_hw_addr_set(obj, hw_addr);
+}
+of_port_mod_mask_set(obj, 4279369489);
+of_port_mod_port_no_set(obj, 65533);
+of_port_mod_xid_set(obj, 2);