const golang.org/x/sys/unix.SizeofInet4Pktinfo

one use

	golang.org/x/sys/unix (current package)
		ztypes_darwin_arm64.go#L270: 	SizeofInet4Pktinfo     = 0xc

The pages are generated with Golds v0.2.8-preview. (GOOS=darwin GOARCH=arm64)