patch applied (packages/unix): Don' t use Fd/FD in foreign decls

[Ian Lynagh]

Wed Apr  4 08:59:30 PDT 2007  Ian Lynagh <igloo at earth.li>
  * Don't use Fd/FD in foreign decls
  Using CInt makes it much easier to verify that it is right, and we won't
  get caught out by possible newtype switches between CInt/Int.

    M ./System/Posix/Files.hsc -4 +4
    M ./System/Posix/Temp.hsc -2 +2
    M ./System/Posix/Terminal.hsc -20 +20