{"ast_node_type":"variable","tokens":[{"end":81,"kind":"keyword","start":0,"text":"let"}]}
                let b_lane0 = b.value_lane(fx, out_lane_idx * 2).load_scalar(fx);
                let a_lane0 = fx.bcx.ins().sextend(types::I32, a_lane0);
                let b_lane0 = fx.bcx.ins().sextend(types::I32, b_lane0);