Compat symlinks for /dev/acd0?

Hi,

When the ATA_CAM option is enabled in the kernel, we create
compatibility symlinks for /dev/ada devices, such as: /dev/ad8s1_at_ -> ada0s1

We don't do this for ATAPI CD-ROM devices.

Any reason *not* to do this for ATAPI CD-ROM devices?  i.e.  /dev/cd0 -> acd0

It's a minor thing, but will definitely hit people who have /dev/acd0
in /etc/fstab when they upgrade to 9.0.
People can read UPDATING and the release notes, but if we can do this
minor thing,
it might make migration easier.

-- 
Craig Rodrigues
rodrigc_at_crodrigues.org