{"ast_node_type":"impl","tokens":[{"end":68,"kind":"keyword","start":0,"text":"compute:"}]}
    compute: impl FnOnce() -> InterpResult<'tcx, TyAndLayout<'tcx>>,
    known_layout: Option<TyAndLayout<'tcx>>,
) -> InterpResult<'tcx, TyAndLayout<'tcx>> {