Block layer patches

- qemu-storage-daemon: Add --daemonize
- Fix x-blockdev-amend and block node activation code which incorrectly
  executed code in the iothread that must run in the main thread.
- Add macros for coroutine-safe TLS variables (required for correctness
  with LTO)
- Fix crashes with concurrent I/O and bdrv_refresh_limits()
- Split block APIs in global state and I/O
- iotests: Don't refuse to run at all without GNU sed, just skip tests
  that need it

# gpg: Signature made Fri 04 Mar 2022 17:18:31 GMT
# gpg:                using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
# gpg:                issuer "kwolf@redhat.com"
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kwolf-gitlab/tags/for-upstream: (50 commits)
  block/amend: Keep strong reference to BDS
  block/amend: Always call .bdrv_amend_clean()
  tests/qemu-iotests: Rework the checks and spots using GNU sed
  iotests/graph-changes-while-io: New test
  iotests: Allow using QMP with the QSD
  block: Make bdrv_refresh_limits() non-recursive
  job.h: assertions in the callers of JobDriver function pointers
  job.h: split function pointers in JobDriver
  block-backend-common.h: split function pointers in BlockDevOps
  block_int-common.h: assertions in the callers of BdrvChildClass function pointers
  block_int-common.h: split function pointers in BdrvChildClass
  block_int-common.h: assertions in the callers of BlockDriver function pointers
  block_int-common.h: split function pointers in BlockDriver
  block/coroutines: I/O and "I/O or GS" API
  block/copy-before-write.h: global state API + assertions
  include/block/snapshot: global state API + assertions
  assertions for blockdev.h global state API
  include/sysemu/blockdev.h: global state API
  assertions for blockjob.h global state API
  include/block/blockjob.h: global state API
  ...

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