Encoding:
    SILC_ASN1_BOOLEAN(boolval)
    SILC_ASN1_BOOLEAN_T(opts, tag, boolval)

    Decoding:
    SILC_ASN1_BOOLEAN(&boolval)
    SILC_ASN1_BOOLEAN_T(opts, tag, &boolval)

    Macro used to encode or decode boolean value.  The boolean type
    is SilcBool.

    The `opts' is SilcAsn1Options.  The `tag' is a tag number.