Add a "panic" method to stevedores, so they can dump the objcores

internal state.

bin/varnishd/cache/cache_panic.c

@@ -258,6 +258,13 @@ pan_objcore(struct vsb *vsb, const char *typ, const struct objcore *oc)
 		if (strlen(oc->stobj->stevedore->ident))
 			VSB_printf(vsb, " %s", oc->stobj->stevedore->ident);
 		VSB_printf(vsb, ")");
+		if (oc->stobj->stevedore->panic) {
+			VSB_printf(vsb, " {\n");
+			VSB_indent(vsb, 2);
+			oc->stobj->stevedore->panic(vsb, oc);
+			VSB_indent(vsb, -2);
+			VSB_printf(vsb, "}");
+		}
 	}
 	VSB_printf(vsb, ",\n");
 	VSB_indent(vsb, -2);

bin/varnishd/storage/storage.h

@@ -71,6 +71,8 @@ typedef int storage_baninfo_f(const struct stevedore *, enum baninfo event,
     const uint8_t *ban, unsigned len);
 typedef void storage_banexport_f(const struct stevedore *, const uint8_t *bans,
     unsigned len);
+typedef void storage_panic_f(struct vsb *vsb, const struct objcore *oc);
+
 
 typedef struct object *sml_getobj_f(struct worker *, struct objcore *);
 typedef struct storage *sml_alloc_f(const struct stevedore *, size_t size);
@@ -97,6 +99,7 @@ struct stevedore {
 	storage_allocobj_f	*allocobj;
 	storage_baninfo_f	*baninfo;
 	storage_banexport_f	*banexport;
+	storage_panic_f		*panic;
 
 	/* Only if SML is used */
 	sml_alloc_f		*sml_alloc;