Where does Slackware get links like /dev/fd from?

In LFS there is a startup script (mountvirtfs) to create the various odd symbolic links that you get in a standard /dev directory: things like /dev/stdin, /dev/core and /dev/fd. It malfunctions on my LFS system so I thought I would compare it with the Slackware equivalent. But there doesn't appear to be a Slackware equivalent. Grepping for these names in the startup scripts of Slackware 15 yields nothing.

So how does Slackware create them? Is it a udev thing? (LFS now uses systemd-udev whereas Slackware uses eudev.)