patch applied (ghc): FIX BUILD FD_SETSIZE signed

[Simon Marlow]

Thu Sep 27 06:26:49 PDT 2007  jochemberndsen at dse.nl
  * FIX BUILD FD_SETSIZE signed
  On FreeBSD FD_SETSIZE is unsigned. Cast it to a signed int
  for portability.

    M ./rts/posix/Select.c -2 +6