References: golang.org/x/sys/unix.TCP_V6

const golang.org/x/sys/unix.TCP_V6_FLOW

one use

	golang.org/x/sys/unix (current package)
		ztypes_linux.go#L4144: 	TCP_V6_FLOW    = 0x5

The pages are generated with Golds v0.7.6. (GOOS=linux GOARCH=amd64)