Fix #9415.
authorRichard Eisenberg <eir@cis.upenn.edu>
Wed, 6 Aug 2014 13:51:26 +0000 (09:51 -0400)
committerRichard Eisenberg <eir@cis.upenn.edu>
Tue, 12 Aug 2014 15:46:20 +0000 (11:46 -0400)
commit1b1388697e687154c2bf1943639e75f3ccf5bc59
tree3a211439c88e47825f201801b7496532a0abf42f
parentf29bdfbcedda6cb33ab05d884c151f2b31f4e4e0
Fix #9415.

Abort typechecking when we detect a superclass cycle error, as
ambiguity checking in the presence of superclass cycle errors can
cause a loop.
compiler/typecheck/TcTyClsDecls.lhs