that is definitely run by the ubsan tinderbox to flush out

cppuhelper/source/exc_thrower.cxx:201:15: runtime error: member call on address
"foo" which does not point to an object of type 'cppuhelper::detail::XExceptionThrower'

Change-Id: Ia798cc6695011480717c1a80d0ab7830080b5de1
Reviewed-on: https://gerrit.libreoffice.org/45244Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>