{"ast_node_type":"variable","tokens":[{"end":76,"kind":"keyword","start":0,"text":"let"}]}
                    let b_lane = b.value_lane(fx, lane_idx).load_scalar(fx);
                    let a_lane = fx.bcx.ins().uextend(types::I16, a_lane);
                    let b_lane = fx.bcx.ins().uextend(types::I16, b_lane);