[Yhc] NYHC parsing of pattern guards

[Neil Mitchell]

Hi

Q1: Where do I send these emails on the shared Yhc/nhc bit? Should we
perhaps merge both into one list?

Q2: There seems to be a bug in the pattern guard parsing:

test
    | a = b
    | Just c <- d = e

Error: C:\DOCUME~2\Uni\yhc\current\inst\bin\StackSet.hs(5:5) Found | but expecte
d a {-end-of-definition-or-EOF-}

This fragment is a reduced test case from StackSet.hs in XMonad. I
would _really_ like to be able to compile that module with Yhc!

Thanks

Neil