Simon Peyton Jones authored Aug 29, 2012 and pcapriotti committed Aug 31, 2012

This change means that we don't recover from erroneous type
declarations, thereby reporting fewer errors.  But trying to
recover confused GHC (leading to a pattern match failure in
the compiler Trac #7175), and it turned out to be tricky
to fix that.

So this patch takes the more conservative path of failing
earlier, perhaps reporting fewer real errors.

MERGED from commit d0ddde58