{"ast_node_type":"variable","tokens":[{"end":95,"kind":"keyword","start":0,"text":"let"}]}
                        let msb = fx.bcx.ins().iconst(types::I64, (delta >> 64) as u64 as i64);
                        let lsb = fx.bcx.ins().iconst(types::I64, delta as u64 as i64);
                        fx.bcx.ins().iconcat(lsb, msb)