Miniobj-ify the compiled backend and probe structs

include/vrt.h

@@ -140,6 +140,8 @@ extern const void * const vrt_magic_string_end;
 extern const void * const vrt_magic_string_unset;
 
 struct vrt_backend_probe {
+	unsigned			magic;
+#define VRT_BACKEND_PROBE_MAGIC		0x84998490
 	const char			*url;
 	const char			*request;
 	double				timeout;
@@ -154,6 +156,8 @@ struct vrt_backend_probe {
  * A backend is a host+port somewhere on the network
  */
 struct vrt_backend {
+	unsigned			magic;
+#define VRT_BACKEND_MAGIC		0x4799ce6b
 	const char			*vcl_name;
 	const char			*ipv4_addr;
 	const char			*ipv6_addr;

lib/libvcc/vcc_backend.c

@@ -126,6 +126,7 @@ vcc_ParseProbeSpec(struct vcc *tl)
 	status = 0;
 	Fh(tl, 0, "static const struct vrt_backend_probe vgc_probe__%d = {\n",
 	    tl->nprobe++);
+	Fh(tl, 0, "\t.magic = VRT_BACKEND_PROBE_MAGIC,\n");
 	while (tl->t->tok != '}') {
 
 		vcc_IsField(tl, &t_field, fs);
@@ -305,6 +306,7 @@ vcc_ParseHostDef(struct vcc *tl, const struct token *t_be)
 	Fb(tl, 0, "\nstatic const struct vrt_backend vgc_dir_priv_%s = {\n",
 	    vgcname);
 
+	Fb(tl, 0, "\t.magic = VRT_BACKEND_MAGIC,\n");
 	Fb(tl, 0, "\t.vcl_name = \"%.*s", PF(t_be));
 	Fb(tl, 0, "\",\n");