tv: Allow irma_twos_complement everywhere where mode_is_int was allowed
tv: Allow irma_twos_complement everywhere where mode_is_int was allowed

pointer modes have irma_tows_complement as well and I don't see why we
shouldn't allow performing tarval operations on them like this.

MatzeB/libfirm,MatzeB/libfirm,libfirm/libfirm,jonashaag/libfirm,MatzeB/libfirm,libfirm/libfirm,MatzeB/libfirm,jonashaag/libfirm,jonashaag/libfirm,jonashaag/libfirm,MatzeB/libfirm,libfirm/libfirm,libfirm/libfirm,jonashaag/libfirm,jonashaag/libfirm,MatzeB/libfirm,libfirm/libfirm,MatzeB/libfirm,jonashaag/libfirm