{"ast_node_type":"variable","tokens":[{"end":81,"kind":"keyword","start":0,"text":"let"}]}
        let mut vis = ImproperCTypesVisitor { cx, mode: CItemKind::Declaration };
    fn check_foreign_item(&mut self, cx: &LateContext<'tcx>, it: &hir::ForeignItem<'tcx>) {
        let abi = cx.tcx.hir_get_foreign_abi(it.hir_id());