Pull nonblocking pipe io_uring support from Jens Axboe:
"Here's the revised edition of the FMODE_NOWAIT support for pipes, in
which we just flag it as such supporting FMODE_NOWAIT unconditionally,
but clear it if we ever end up using splice/vmsplice on the pipe.
The pipe read/write side is perfectly fine for nonblocking IO, however
splice and vmsplice can potentially wait for IO with the pipe lock
held"
* tag 'pipe-nonblock-2023-05-06' of git://git.kernel.dk/linux:
pipe: set FMODE_NOWAIT on pipes
splice: clear FMODE_NOWAIT on file if splice/vmsplice is used