param_env: ty::ParamEnv<'tcx>,
) -> DefIdForest<'tcx> {
let data_uninhabitedness = move || self.ty(tcx, substs).uninhabited_from(tcx, param_env);
param_env: ty::ParamEnv<'tcx>,
) -> DefIdForest<'tcx> {
let data_uninhabitedness = move || self.ty(tcx, substs).uninhabited_from(tcx, param_env);