Revert "vectoriser: workaround bug in classiftTyCons"

This reverts commit acbb3dba.

compiler/vectorise/Vectorise/Type/Classify.hs

@@ -43,15 +43,7 @@ classifyTyCons :: UniqFM Bool                     -- ^type constructor conversio
                -> ([TyCon], [TyCon], [TyCon])     -- ^tycons to be converted & not to be converted
 classifyTyCons convStatus tcs = classify [] [] [] convStatus (tyConGroups tcs)
   where
-
---  ******** HACKS *********
---  TyCons that were marked as 'keep' are instead put into the 'conv' list, 
---  because keeping them was breaking the nbody example. 
---  This needs to be fixed. -- BL 29/11/2011
---  classify conv keep ignored _  [] = (conv, keep, ignored)
-    classify conv keep ignored _  [] = (conv ++ keep, [], ignored)
---  ************************
-
+    classify conv keep ignored _  [] = (conv, keep, ignored)
     classify conv keep ignored cs ((tcs, ds) : rs)
       | can_convert && must_convert
       = classify (tcs ++ conv) keep ignored (cs `addListToUFM` [(tc, True) | tc <- tcs]) rs