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

one use

	golang.org/x/sys/unix (current package)
		zsysnum_linux_amd64.go#L309: 	SYS_RECVMMSG                = 299

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