his Fifth Amendment privilege to resist cross- examination on matters reasonably related ts to those brought ou 'n direct examination. See, e.g., McGautha . California, 402 U.S. 183, 215, 91 S.Ct. 1 54, 1471, 28 L.Ed.2d 711 (1971).ms FN14. What constitutes a waiver with respect to work-product mater