jvs/jvs-util.c: Add JVS dispatch helper

jvs/jvs-util.h

@@ -0,0 +1,21 @@
+#pragma once
+
+#include <windows.h>
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "hook/iobuf.h"
+
+typedef HRESULT (*jvs_dispatch_fn_t)(
+        void *ctx,
+        struct const_iobuf *req,
+        struct iobuf *resp);
+
+void jvs_crack_request(
+        const void *bytes,
+        size_t nbytes,
+        struct iobuf *resp,
+        uint8_t jvs_addr,
+        jvs_dispatch_fn_t dispatch_fn,
+        void *dispatch_ctx);