Re: pgsql: Fix timing issue in new subscription truncate test

I wrote:
> Testing the fix here, I just noticed that there's a pre-existing
> problem in subscription/t/002_types.pl.  It passes make check OK,
> but make installcheck not so much.  Investigating ...

Oh ... digging into that, it's because that test depends on hstore,
which I hadn't installed.  How much is that dependency really
buying us?  If there's a good reason to have it, we should
(a) document the requirement in src/test/subscription/README,
and (b) try to make the failure less obscure.  I do not really find
this to be an acceptable spelling of "you didn't install hstore":

t/001_rep_changes.pl .. ok
t/002_types.pl ........ # Looks like your test exited with 29 before it could output anything.
t/002_types.pl ........ Dubious, test returned 29 (wstat 7424, 0x1d00)
Failed 3/3 subtests
t/003_constraints.pl .. ok
t/004_sync.pl ......... ok
t/005_encoding.pl ..... ok
t/006_rewrite.pl ...... ok
t/007_ddl.pl .......... ok
t/008_diff_schema.pl .. ok
t/009_matviews.pl ..... ok
t/010_truncate.pl ..... ok

Test Summary Report
-------------------
t/002_types.pl      (Wstat: 7424 Tests: 0 Failed: 0)
  Non-zero exit status: 29
  Parse errors: Bad plan.  You planned 3 tests but ran 0.
Files=10, Tests=45, 56 wallclock secs ( 0.07 usr  0.03 sys + 32.69 cusr 10.18 csys = 42.97 CPU)
Result: FAIL

            regards, tom lane