kernel has faccessat2 since version 4.18.0-252.el8 (see bug 1333764), but glibc doesn't yet have it in syscall-names.list, which causes tst-syscall-list to fail. I ran into this while testing glibc rebuild on POWER10.
Arjun, Thanks for testing. We already had open 1871386 to backport the linux 5.8 syscall names which will fix this bug. *** This bug has been marked as a duplicate of bug 1871386 ***