[commit: ghc] supercompiler: Fix mkSymCo so it actually creates a symmetric coercion (cfa06bc)

Repository : ssh://darcs.haskell.org//srv/darcs/ghc

On branch  : supercompiler

http://hackage.haskell.org/trac/ghc/changeset/cfa06bc2a3ea558f0b5eb7636f5fe29ca809542d

>---------------------------------------------------------------

commit cfa06bc2a3ea558f0b5eb7636f5fe29ca809542d
Author: Max Bolingbroke <[email protected]>
Date:   Tue Oct 23 17:59:58 2012 +0100

    Fix mkSymCo so it actually creates a symmetric coercion

>---------------------------------------------------------------

 compiler/supercompile/Supercompile/Core/Syntax.hs |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/compiler/supercompile/Supercompile/Core/Syntax.hs b/compiler/supercompile/Supercompile/Core/Syntax.hs
index f818383..2084c31 100644
--- a/compiler/supercompile/Supercompile/Core/Syntax.hs
+++ b/compiler/supercompile/Supercompile/Core/Syntax.hs
@@ -20,14 +20,17 @@ import Id       (Id, isId, idType, idInlinePragma)
 import PrimOp   (primOpType)
 import Literal  (Literal, literalType)
 import Type     (Type, mkTyVarTy, applyTy, applyTys, mkForAllTy, mkFunTy, splitFunTy_maybe, eqType)
+import TypeRep  (Type(..))
+import Kind
 import Coercion (CoVar, Coercion, coercionType, coercionKind, mkCvSubst, mkAxInstCo, mkReflCo, isReflCo)
+import qualified Coercion as Coercion
 import PrimOp   (PrimOp)
 import Pair     (pSnd)
 import PprCore  ()
 
 
 mkSymCo :: InScopeSet -> NormalCo -> NormalCo
-mkSymCo iss co = optCoercion (mkCvSubst iss []) co
+mkSymCo iss co = optCoercion (mkCvSubst iss []) (Coercion.mkSymCo co)
 
 mkTransCo :: InScopeSet -> NormalCo -> NormalCo -> NormalCo
 mkTransCo = opt_trans