supporting GHC 7.8rc1. (#186)

from @bartavelle.

Language/Haskell/GhcMod/Gap.hs

@@ -55,6 +55,8 @@ import qualified Pretty
 import qualified StringBuffer as SB
 #if __GLASGOW_HASKELL__ >= 707
 import FamInstEnv
+import ConLike (ConLike(..))
+import PatSyn (patSynType)
 #else
 import TcRnTypes
 #endif
@@ -339,6 +341,11 @@ data GapThing = GtI Id | GtD DataCon | GtT TyCon | GtN
 
 fromTyThing :: TyThing -> GapThing
 fromTyThing (AnId i)                   = GtI i
+#if __GLASGOW_HASKELL__ >= 707
+fromTyThing (AConLike (RealDataCon d)) = GtD d
+fromTyThing (AConLike (PatSynCon d))   = GtD d
+#else
 fromTyThing (ADataCon d)               = GtD d
+#endif
 fromTyThing (ATyCon t)                 = GtT t
 fromTyThing _                          = GtN