atime preservation

[Roland McGrath]

POSIX does not require that readlink affect atime.  So perhaps you just
want to argue with the Linux kernel people for it never changing atime.

In the Hurd, you can open a symlink with O_NOLINK to get the symlink node
itself (as lstat does vs stat), so an freadlink that takes such an fd is
the most natural interface to add.  But you really need to figure out what,
if anything, you can get added to the Linux kernel.