{"ast_node_type":"other","tokens":[{"end":79,"kind":"keyword","start":0,"text":"//"}]}
        // https://github.com/rust-lang/rust/pull/85158#issuecomment-1101836457
        // understood, so we conservatively treat this optimization as unsound:
        sess.opts.unstable_opts.unsound_mir_opts || sess.mir_opt_level() >= 3