Add handshake interface support for gVisor UDP

stack_lwip_stub.go

@@ -0,0 +1,11 @@
+//go:build !with_lwip
+
+package tun
+
+import E "github.com/sagernet/sing/common/exceptions"
+
+func NewLWIP(
+	options StackOptions,
+) (Stack, error) {
+	return nil, E.New(`LWIP is not included in this build, rebuild with -tags with_lwip`)
+}