initdb and fsync

It looks like initdb doesn't fsync all the files it creates, e.g. the
PG_VERSION file.

While it's unlikely that it would cause any real data loss, it can be
inconvenient in some testing scenarios involving VMs.

Thoughts? Would a patch to add a few fsync calls to initdb be accepted?
Is a platform-independent fsync be available at initdb time?

Regards,
    Jeff Davis