Function rustc_typeck::check::get_owner_return_paths

pub(in check) fn get_owner_return_paths<'tcx>(
    tcx: TyCtxt<'tcx>, 
    def_id: LocalDefId
) -> Option<(HirId, ReturnsVisitor<'tcx>)>

Given a DefId for an opaque type in return position, find its parent item's return expressions.