patch applied (ghc): Keep valgrind happy when calling timer_create

[Sven Panne]

Sun Sep 16 04:19:27 PDT 2007  sven.panne at aedion.de
  * Keep valgrind happy when calling timer_create
  Fill all of the sigevent structure with zeroes before individual fields are
  set. Although not strictly necessary, this keeps tools like valgrind from
  complaining about passing uninitialized data, which is a good thing.
  
  MERGE TO STABLE

    M ./rts/posix/Itimer.c +5