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

one use

	golang.org/x/sys/unix (current package)
		ztypes_linux.go#L945: 	CTRL_ATTR_MCAST_GRP_UNSPEC = 0x0

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