{"ast_node_type":"variable","tokens":[{"end":51,"kind":"keyword","start":0,"text":"let"}]}
    let instance = ty::Instance::mono(tcx, def_id);
    let def_id = tcx.require_lang_item(li, span);
    (bx.fn_abi_of_instance(instance, ty::List::empty()), bx.get_fn_addr(instance), instance)