Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into staging

# gpg: Signature made Tue 27 Mar 2018 15:41:11 BST
# gpg:                using RSA key 9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha/tags/block-pull-request:
  MAINTAINERS: add include/block/aio-wait.h
  coroutine: add test-aio coroutine queue chaining test case
  coroutine: avoid co_queue_wakeup recursion
  queue: add QSIMPLEQ_PREPEND()

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