patch applied (ghc): exprIsHNF should "look through" lets

[Simon Peyton Jones]

Tue Nov 17 04:55:26 PST 2009  simonpj at microsoft.com
  * exprIsHNF should "look through" lets
  Ignore-this: 3e77d029c0f314c53171f0378939b496
  
  I can't quite remember when I spotted this, but exprIsHNF (and
  similarly exprIsConLike) should ignore enclosing let-bindings,
  since they don't affect termination.

    M ./compiler/coreSyn/CoreUtils.lhs +1

View patch online:
http://darcs.haskell.org/ghc/_darcs/patches/20091117125526-1287e-a57a927bf99830488808cc179040afd6f482e9d0.gz