Merge PR #55457 into main

* refs/pull/55457/head:
	client: check for bad file handle in low level I/O APIs
	client: check for bad file handle in ll_preadv_pwritev
	client: add function to check if file handle exists
	src/test: test async I/O with invalid/closed file handle

Reviewed-by: Venky Shankar <vshankar@redhat.com>

diff --cc src/client/Client.cc
Simple merge

diff --cc src/client/Client.h
Simple merge