const golang.org/x/sys/unix.NFT_EXTHDR_OP_IPV6

one use

	golang.org/x/sys/unix (current package)
		ztypes_linux.go#L2103: 	NFT_EXTHDR_OP_IPV6                = 0x0

The pages are generated with Golds v0.4.9. (GOOS=linux GOARCH=amd64)