So, the xfs filesystem really prefers to use 64-bit inode numbers on large filesystems; btrfs would like 64-bit inodes and ext4 is considering it as well. Is the world ready for this? not yet. Running a tool written by Greg Banks over the binary directories in all x86 Fedora Rawhide packages, it comes up with:
4070 29.1% are scripts (shell, perl, whatever) 6598 47.2% don't use any stat() family calls at all 1829 13.1% use 32-bit stat() family interfaces only 1312 9.4% use 64-bit stat64() family interfaces only 180 1.3% use both 32-bit and 64-bit stat() family interfaces
I need to correlate this with packages that actually use the st_ino stat field, but a spot-check so far includes postfix and sendmail. 
But, we have the technology, we can fix it!
On edit: ugh, I forgot to scan the libraries. It’s worse than I thought.