RELNOTES: Document file handle layout changes

[rmacklem]

Looks fine to me.

[imp]

This seems like a rare time we ahould also put 8t in UPDATING.

[markj]

Update UPDATING.

[olce]

Thanks. But while we're here, shouldn't it wait for D47956 as well? Going to update it in a short while to separate the change of switching the generation number to 32 bits to another revision so that the rest can be reviewed and hopefully approved/committed shortly.

[markj]

In D48093#1096464, @olce wrote:

Thanks. But while we're here, shouldn't it wait for D47956 as well? Going to update it in a short while to separate the change of switching the generation number to 32 bits to another revision so that the rest can be reviewed and hopefully approved/committed shortly.

Sure, I will wait for that revision.