{"ast_node_type":"other","tokens":[{"end":36,"kind":"keyword","start":0,"text":"infcx:"}]}
    infcx: &BorrowckInferCtxt<'tcx>,
    universal_regions: &UniversalRegions<'tcx>,
) -> (Frozen<IndexVec<RegionVid, RegionDefinition<'tcx>>>, bool) {