{"ast_node_type":"other","tokens":[{"end":67,"kind":"keyword","start":0,"text":"//"}]}
    // This is an underapproximation of `BikeshedGuaranteedNoDrop`,
    // If `BikeshedGuaranteedNoDrop` is not defined in a `#[no_core]` test, fall back to `Copy`.
    let def_id = tcx