Invariant_paramsval invariant_params_in_recursion : Flambda.function_declarations -> backend:(module Backend_intf.S) -> Variable.Set.t Variable.Map.tval invariant_param_sources : Flambda.function_declarations -> backend:(module Backend_intf.S) -> Variable.Pair.Set.t Variable.Map.tval unused_arguments : Flambda.function_declarations -> backend:(module Backend_intf.S) -> Variable.Set.t