patch applied (ghc): Add extra WARN test

[Simon Peyton Jones]

Wed Sep 17 09:24:34 PDT 2008  simonpj at microsoft.com
  * Add extra WARN test
  
  This warning tests that the arity of a function does not decrease.
  And that it's at least as great as the strictness signature.
  
  Failing this test isn't a disater, but it's distinctly odd and 
  usually indicates that not enough information is getting propagated
  around, and hence you may get more simplifier iterations.
  

    M ./compiler/simplCore/Simplify.lhs -2 +15

View patch online:
http://darcs.haskell.org/ghc/_darcs/patches/20080917162434-1287e-2abb9bb0d303cca7382e7cab69b4802a4353df84.gz