Import 4.4BSD-Lite2 onto the vendor branch, note that in the kernel, all
    files are off the vendor branch, so this should not change anything.
    
    A "U" marker generally means that the file was not changed in between
    the 4.4Lite and Lite-2 releases, and does not need a merge.  "C" generally
    means that there was a change.
    [note, new file: cd9660_mount.h]