{"ast_node_type":"variable","tokens":[{"end":92,"kind":"keyword","start":0,"text":"let"}]}
    let source = MirSource::from_instance(ty::InstanceKind::FnPtrAddrShim(def_id, self_ty));
    );
    new_body(source, IndexVec::from_elem_n(start_block, 1), locals, sig.inputs().len(), span)