{"ast_node_type":"other","tokens":[{"end":79,"kind":"keyword","start":0,"text":"//"}]}
    // predicates, it will shrink the MIR to a single `unreachable` terminator.
    // If `mir_drops_elaborated_and_const_checked` found that the current body has unsatisfiable
    // More generally, if MIR is a lone `unreachable`, there is nothing to optimize.