block: introduce block_io_start/block_io_done tracepoints

block: introduce block_io_start/block_io_done tracepoints

Currently, several BCC ([0]) tools (biosnoop/biostacks/biotop) use
kprobes to blk_account_io_start/blk_account_io_done to implement
their functionalities. This is fragile because the target kernel
functions may be renamed ([1]) or inlined ([2]). So introduce two
new tracepoints for such use cases.

  [0]: https://github.com/iovisor/bcc
  [1]: https://github.com/iovisor/bcc/issues/3954
  [2]: https://github.com/iovisor/bcc/issues/4261

Tested-by: Francis Laniel <flaniel@linux.microsoft.com>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Tested-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20230520084057.1467003-1-hengqi.chen@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>