s390x/tcg: Implement VECTOR MULTIPLY AND ADD *

s390x/tcg: Implement VECTOR MULTIPLY AND ADD *

Quite some variants to handle. At least handle some 32-bit element
variants via gvec expansion (we could also handle 16/32-bit variants
for ODD and EVEN easily via gvec expansion, but let's keep it simple
for now).

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