import CoreFVs -- all of it
import CoreSubst ( Subst, emptySubst, extendInScope, extendIdSubst,
cloneIdBndr, cloneRecIdBndrs )
-import Id ( Id, idType, mkSysLocal, isOneShotLambda,
+import Id ( idType, mkSysLocal, isOneShotLambda,
zapDemandIdInfo, transferPolyIdInfo,
idSpecialisation, idWorkerInfo, setIdInfo
)