test/isolation/expected/stats_1.out broken for me

Running installcheck-world on an unrelated patch, I noticed a failure
here in test/isolation/expected/stats_1.out (this is line 3102):

step s1_slru_check_stats:
         SELECT current.blks_zeroed > before.value
   FROM test_slru_stats before
   INNER JOIN pg_stat_slru current
   ON before.slru = current.name
   WHERE before.stat = 'blks_zeroed';

?column?
--------
t
(1 row)

This is built from bab588c. On my amd64/linux box the result is f.

The same mismatch is present if I build from 6392f2a (i.e., just before
a2f433f pgstat: add alternate output for stats.spec), along with
a bunch of others. So a2f433f seems to have silenced all the rest
of those, but not this one.

If I build from ad40166, installcheck-world passes. That's as far
as I have pursued it.

Regards,
-Chap