{"ast_node_type":"other","tokens":[{"end":88,"kind":"keyword","start":0,"text":"//"}]}
            // FIXME(#132279): what is this, why are we using an empty environment here.
        let eval_mono_const = |constant: &ConstOperand<'tcx>| {
            let typing_env = ty::TypingEnv::fully_monomorphized();