Merge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2021-10-15' into staging

nbd patches for 2021-10-15

- Vladimir Sementsov-Ogievskiy: Consistent use of 64-bit parameters in
  block operations
- Hanna Reitz: Silence 32-bit compiler warning

# gpg: Signature made Fri 15 Oct 2021 02:08:10 PM PDT
# gpg:                using RSA key 71C2CC22B1C4602927D2F3AAA7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>" [full]
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>" [full]
# gpg:                 aka "[jpeg image of size 6874]" [full]

* remotes/ericb/tags/pull-nbd-2021-10-15:
  block-backend: update blk_co_pwrite() and blk_co_pread() wrappers
  block-backend: fix blk_co_flush prototype to mention coroutine_fn
  block-backend: drop INT_MAX restriction from blk_check_byte_request()
  block-backend: blk_pread, blk_pwrite: rename count parameter to bytes
  block-backend: convert blk_aio_ functions to int64_t bytes paramter
  block-backend: convert blk_co_copy_range to int64_t bytes
  block-backend: convert blk_foo wrappers to use int64_t bytes parameter
  block-backend: drop blk_prw, use block-coroutine-wrapper
  block-coroutine-wrapper.py: support BlockBackend first argument
  block-backend: rename _do_ helper functions to _co_do_
  block-backend: convert blk_co_pdiscard to int64_t bytes
  block-backend: convert blk_co_pwritev_part to int64_t bytes
  block-backend: make blk_co_preadv() 64bit
  block-backend: blk_check_byte_request(): int64_t bytes
  qcow2: Silence clang -m32 compiler warning

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>