Merge remote-tracking branch 'remotes/rth/tags/pull-i386-20160215' into staging

Add XSAVE, MPX, FSGSBASE.

# gpg: Signature made Mon 15 Feb 2016 11:21:50 GMT using RSA key ID 4DD0279B
# gpg: Good signature from "Richard Henderson <rth7680@gmail.com>"
# gpg:                 aka "Richard Henderson <rth@redhat.com>"
# gpg:                 aka "Richard Henderson <rth@twiddle.net>"

* remotes/rth/tags/pull-i386-20160215:
  target-i386: Implement FSGSBASE
  target-i386: Enable CR4/XCR0 features for user-mode
  target-i386: Clear bndregs during legacy near jumps
  target-i386: Implement BNDLDX, BNDSTX
  target-i386: Update BNDSTATUS for exceptions raised by BOUND
  target-i386: Implement BNDCL, BNDCU, BNDCN
  target-i386: Implement BNDMOV
  target-i386: Implement BNDMK
  target-i386: Split up gen_lea_modrm
  target-i386: Perform set/reset_inhibit_irq inline
  target-i386: Enable control registers for MPX
  target-i386: Implement XSAVEOPT
  target-i386: Add XSAVE extension
  target-i386: Rearrange processing of 0F AE
  target-i386: Rearrange processing of 0F 01
  target-i386: Split fxsave/fxrstor implementation

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