s390x/tcg: Define vector instruction formats

s390x/tcg: Define vector instruction formats

These are the new instruction formats related to vector instructions as
up to the z14 (a.k.a. latest PoP).

As v2 appeares (like x2 in VRX) with d2/b2 in VRV, we have to assign it a
higher field number to avoid collisions.

Properly take care of the MSB (to be able to address 32 registers) for
each vector register field stored in the RXB field (Bit 36 - 30  for all
vector instructions). As we have 32 bit vector registers and the
"v" fields are only 4 bit in size, the 5th bit is stored in the RXB.
We use a new type to indicate that the MSB has to be fetched from the
RXB.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20190307121539.12842-2-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>