target-s390: Tidy comparisons After full conversion, we can audit the uses of LTGT cc ops and see that none of the instructions can ever set CC=3. Thus we can extend the table to treat that bit as ignored. This fixes a regression wrt the pre-conversion translation in which NE was used for both m=6 and m=7. Signed-off-by: Richard Henderson <rth@twiddle.net>