Fix crash printing packed record with packed array.

    Fix crash printing packed record with packed array.

        * ada-lang.c (ada_modulus_from_name): New function.
        (ada_modulus): In the case where the type length is bigger than
        the size of the type used to hold the bounds, try determining
        the modulus from the type name.
        (ada_value_primitive_packed_val): Fix bug in the computation of
        ntarg causing an out-of-buffer invalid access.