patch applied (testsuite): Add if_os, and change derefnull/divbyzero to use it

[Ian Lynagh]

Sun Apr 20 12:42:51 PDT 2008  Ian Lynagh <igloo at earth.li>
  * Add if_os, and change derefnull/divbyzero to use it
  I think different Linux setups generate different output for these tests,
  so we just ignore the output on Linux now.

    M ./driver/testglobals.py +1
    M ./driver/testlib.py +6
    M ./mk/test.mk +1
    M ./tests/ghc-regress/rts/all.T -6 +15

View patch online:
http://darcs.haskell.org/testsuite/_darcs/patches/20080420194251-3fd76-b006013c54a68a8b62376976d5b4ba0c4c88da23.gz