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

one use

	golang.org/x/sys/unix (current package)
		ztypes_linux.go#L1002: 	CTRL_CMD_GETMCAST_GRP      = 0x9

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