Merge remote-tracking branch 'remotes/ehabkost/tags/x86-pull-request' into staging

x86 bug fixes

Fix for a XSAVE regression when using "-cpu host", and a fix on
the Opteron_G3 CPU model.

# gpg: Signature made Mon 03 Oct 2016 20:08:13 BST
# gpg:                using RSA key 0x2807936F984DC5A6
# gpg: Good signature from "Eduardo Habkost <ehabkost@redhat.com>"
# Primary key fingerprint: 5A32 2FD5 ABC4 D3DB ACCF  D1AA 2807 936F 984D C5A6

* remotes/ehabkost/tags/x86-pull-request:
  target-i386: Correct family/model/stepping for Opteron_G3
  target-i386: Report known CPUID[EAX=0xD,ECX=0]:EAX bits as migratable

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