Re: WIP: a way forward on bootstrap data

Attached is a round of minor review fixes. Much of this is cleaning
up existing mistakes or out-of-date comments, rather than anything
introduced by this patchset, but I noticed it while going through the
patch.

The additional EXPOSE_TO_CLIENT_CODE bits actually are necessary,
in some cases, as I had compile failures without them after changing
client include lines. (I'll post that separately.)

I added a couple more BKI_DEFAULT markers here, but omitted the ensuing
.dat file updates, because they're just mechanical.

I don't think there's any great need to incorporate this into your patch
set. As far as I'm concerned, v14 is ready as-is, and I'll just apply
this over the top of it. (Note that I'll probably smash the whole thing
to one commit when the time comes.)

I have some other work pending on the documentation aspect, but that's
not quite ready for public consumption yet.

regards, tom lane