patch applied (ghc): don't overwrite io_manager_pipe if it is already set

[Simon Marlow]

Thu Apr 23 04:29:39 PDT 2009  Simon Marlow <marlowsd at gmail.com>
  * don't overwrite io_manager_pipe if it is already set
  Ignore-this: 8e7d94a051b4b3daec89ea3103678550
  Part of the fix for #3171

    M ./rts/posix/Signals.c -1 +3

View patch online:
http://darcs.haskell.org/ghc/_darcs/patches/20090423112939-12142-c3a9020bc5c13f9ad60e3b706606c71558986a04.gz