Merge PR #20373 into master

* refs/pull/20373/head:
	client: clamp I/O sizes to INT_MAX when we can't return larger values
	test: new testcase for ceph_ll_readv and ceph_ll_writev
	client: hook up ceph_ll_readv and ceph_ll_writev
	client: type safety cleanup for _read and _write codepaths

Reviewed-by: Gregory Farnum <gfarnum@redhat.com>
Reviewed-by: Patrick Donnelly <pdonnell@redhat.com>
Reviewed-by: Greg Farnum <gfarnum@redhat.com>

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