Update GHC2Core.hs
Update GHC2Core.hs

It's quick fix for error:
*** Exception: CLaSH.GHC.GHC2Core(180): Can't convert PrimRep: Word64Rep in tycon: GHC.Prim.Word64#
ggreif/clash-compiler,ggreif/clash-compiler,christiaanb/clash-compiler,christiaanb/clash-compiler