pp_vanilla_decl_head :: OutputableBndr name
   => Located name
   -> LHsTyVarBndrs name
   -> HsContext name
   -> SDoc
pp_vanilla_decl_head thing tyvars context
 = hsep [pprHsContext context, pprPrefixOcc (unLoc thing), ppr tyvars]
pp_vanilla_decl_head :: OutputableBndr name
   => Located name
   -> LHsTyVarBndrs name
   -> HsContext name
   -> SDoc
pp_vanilla_decl_head thing tyvars context
 = hsep [pprHsContext context, pprPrefixOcc (unLoc thing), ppr tyvars]
pp_vanilla_decl_head thing tyvars context
 = hsep [pprHsContext context, pprPrefixOcc (unLoc thing), ppr tyvars]