Selectivity tests failing under PG18

[robe2]

I was testing this against both mys2/minw64 and my binaries against PG18 EDB windows shipped. In both cases the selectivity tests fail.

I'm assuming it's a PG18 issue rather than the windows platform, because the tests pass under my PG17 install.

At a glance I think it's because PG18 now includes Buffers in the explain output without needing to specify buffers.

Attached is the idff

pg18regression.diffs.txt

[esabol]

Oh, I initially read this as selectivity was completely broken on PostgreSQL 18, but they just changed the output of EXPLAIN. Whew! We should still fix that, of course, but that should be much easier to fix. Thanks for the report.