Re: plperl: update ppport.h and fix configure version check

=?utf-8?Q?Dagfinn_Ilmari_Manns=C3=A5ker?= <ilmari@ilmari.org> writes:
> Andres' recent post¹ about PL/Perl on Windows and linked-to² patch
> containing an erroneous version check made me realise that we haven't
> updated our copy of ppport.h since 2009.  Attached is a patch that does
> that, and applies code changes suggested by running it.  I've tested
> `make check-world` with `--with-perl` on both the oldest (5.8.9) and
> newest (5.34.0) perls I have handy.

I haven't looked at this patch's details, but I can confirm that it
also builds and passes regression on prairiedog's 5.8.3 perl.

> I also noticed that PL/Perl itself (via plc_perlboot.pl) requires Perl
> 5.8.1, but configure only checks for 5.8 (i.e. 5.8.0).  The second patch
> updates the latter to match.

Hmm ... Perl 5.8.x is old enough that probably it matters to nobody in
the real world, but if we're going to mess with this, is 5.8.1 the right
cutoff?  I wonder about this because I believe prairiedog's perl to be
the oldest that we have tested in a good long while, so that we shouldn't
assert with any confidence that 5.8.1 would actually work.  The last
time I surveyed the buildfarm's perl versions, in 2017, these were the
only 5.8.x animals:

 Animal        | Surveyed build      | Configure's version report
 castoroides   | 2017-07-27 12:03:05 | configure: using perl 5.8.4
 protosciurus  | 2017-07-27 13:24:42 | configure: using perl 5.8.4
 prairiedog    | 2017-07-27 22:51:11 | configure: using perl 5.8.6
 aholehole     | 2017-07-27 19:31:40 | configure: using perl 5.8.8
 anole         | 2017-07-28 00:27:38 | configure: using perl 5.8.8
 arapaima      | 2017-07-27 19:30:52 | configure: using perl 5.8.8
 gharial       | 2017-07-27 20:26:16 | configure: using perl 5.8.8
 locust        | 2017-07-28 00:13:01 | configure: using perl 5.8.8
 narwhal       | 2017-03-17 05:00:02 | configure: using perl 5.8.8
 gaur          | 2017-07-22 21:02:43 | configure: using perl 5.8.9
 pademelon     | 2017-07-22 23:56:59 | configure: using perl 5.8.9

Notice that here, prairiedog is running 5.8.6, which is Apple's
vendor-installed perl on that stone-age version of macOS.
Shortly after that, I *downgraded* it to 5.8.3.  I do not recall
exactly why I chose that precise perl version, but it seems
pretty likely that the reason was "I couldn't get anything older
to build".

In short: (a) we're not testing against anything older than 5.8.3
and (b) it seems quite unlikely that anybody cares about 5.8.x anyway.
So if we want to mess with this, maybe we should set the cutoff
to 5.8.3 not 5.8.1.

            regards, tom lane