Merge remote-tracking branch 'remotes/rth/tags/pull-i386-20160314' into staging

target-i386 fixes

# gpg: Signature made Mon 14 Mar 2016 17:54:06 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-i386-20160314:
  target-i386: Dump unknown opcodes with -d unimp
  target-i386: Fix inhibit irq mask handling
  target-i386: Use gen_nop_modrm for prefetch instructions
  target-i386: Fix addr16 prefix
  target-i386: Fix SMSW for 64-bit mode
  target-i386: Fix SMSW and LMSW from/to register
  target-i386: Avoid repeated calls to the bnd_jmp helper
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>