Function rustc_hir_analysis::check::wfcheck::check_return_position_impl_trait_in_trait_bounds

fn check_return_position_impl_trait_in_trait_bounds<'tcx>(
    wfcx: &WfCheckingCtxt<'_, 'tcx>,
    fn_def_id: LocalDefId,
    fn_output: Ty<'tcx>,
    span: Span
)

Basically check_associated_type_bounds, but separated for now and should be deduplicated when RPITITs get lowered into real associated items.