Merge remote-tracking branch 'remotes/cohuck/tags/s390x-20190311' into staging

s390x update:
- clean up LowCore definition
- first part of vector instruction support for tcg

# gpg: Signature made Mon 11 Mar 2019 08:59:02 GMT
# gpg:                using RSA key C3D0D66DC3624FF6A8C018CEDECF6B93C6F02FAF
# gpg:                issuer "cohuck@redhat.com"
# gpg: Good signature from "Cornelia Huck <conny@cornelia-huck.de>" [unknown]
# gpg:                 aka "Cornelia Huck <huckc@linux.vnet.ibm.com>" [full]
# gpg:                 aka "Cornelia Huck <cornelia.huck@de.ibm.com>" [full]
# gpg:                 aka "Cornelia Huck <cohuck@kernel.org>" [unknown]
# gpg:                 aka "Cornelia Huck <cohuck@redhat.com>" [unknown]
# Primary key fingerprint: C3D0 D66D C362 4FF6 A8C0  18CE DECF 6B93 C6F0 2FAF

* remotes/cohuck/tags/s390x-20190311: (33 commits)
  s390x/tcg: Implement VECTOR UNPACK *
  s390x/tcg: Implement VECTOR STORE WITH LENGTH
  s390x/tcg: Implement VECTOR STORE MULTIPLE
  s390x/tcg: Implement VECTOR STORE ELEMENT
  s390x/tcg: Implement VECTOR STORE
  s390x/tcg: Provide probe_write_access helper
  s390x/tcg: Implement VECTOR SIGN EXTEND TO DOUBLEWORD
  s390x/tcg: Implement VECTOR SELECT
  s390x/tcg: Implement VECTOR SCATTER ELEMENT
  s390x/tcg: Implement VECTOR REPLICATE IMMEDIATE
  s390x/tcg: Implement VECTOR REPLICATE
  s390x/tcg: Implement VECTOR PERMUTE DOUBLEWORD IMMEDIATE
  s390x/tcg: Implement VECTOR PERMUTE
  s390x/tcg: Implement VECTOR PACK *
  s390x/tcg: Implement VECTOR MERGE (HIGH|LOW)
  s390x/tcg: Implement VECTOR LOAD WITH LENGTH
  s390x/tcg: Implement VECTOR LOAD VR FROM GRS DISJOINT
  s390x/tcg: Implement VECTOR LOAD VR ELEMENT FROM GR
  s390x/tcg: Implement VECTOR LOAD TO BLOCK BOUNDARY
  s390x/tcg: Implement VECTOR LOAD MULTIPLE
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>