feat: Waku v2 bridge

Issue #12610

vendor/github.com/anacrolix/mmsg/socket/msghdr_bsdvar.go

@@ -0,0 +1,16 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build darwin dragonfly freebsd netbsd
+
+package socket
+
+func (h *msghdr) setIov(vs []iovec) {
+	l := len(vs)
+	if l == 0 {
+		return
+	}
+	h.Iov = &vs[0]
+	h.Iovlen = int32(l)
+}