s390x/tcg: Implement VECTOR COMPARE *

s390x/tcg: Implement VECTOR COMPARE *

To carry out the comparison, we can reuse the existing gvec comparison
function. In case the CC is to be computed, save the result vector
and compute the CC lazily. The result is a vector consisting of all 1's
for elements that matched and 0's for elements that didn't match.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Hildenbrand <david@redhat.com>