Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging

* Miscellaneous exec.c fixes (Markus, myself)
* Q35 support for -machine kernel_irqchip=split (Rita)
* Chardev replay support (Pavel)
* icount "warping" cleanups (Pavel)

# gpg: Signature made Tue 15 Mar 2016 17:24:08 GMT using RSA key ID 78C7AE83
# gpg: Good signature from "Paolo Bonzini <[email protected]>"
# gpg:                 aka "Paolo Bonzini <[email protected]>"

* remotes/bonzini/tags/for-upstream:
  icount: decouple warp calls
  icount: remove obsolete warp call
  replay: character devices
  exec: fix early return from ram_block_add
  exec: Fix memory allocation when memory path isn't on hugetlbfs
  exec: Fix memory allocation when memory path names new file
  update-linux-headers: Add userfaultfd.h
  kvm: x86: q35: Add support for -machine kernel_irqchip=split for q35

Signed-off-by: Peter Maydell <[email protected]>