Why do we have perl and sed versions of Gen_dummy_probes?

Hi,

I wanted to apply https://postgr.es/m/CAGRY4nwaiPJc8wO0G7WZCgBmATC3GJVgvBoADZHDbCzhj8zTPw@mail.gmail.com
and noticed that there's not just Gen_dummy_probes.sed but also a
Gen_dummy_probes.pl.

I understand why we don't want to rely on sed because of windows - but
it's far from obvious why we can't just use the .pl variant all the
time?

The perl version was introduced in

commit 5d0320105699c253fe19b8b42ae1bffb67785b02
Author: Andrew Dunstan <andrew(at)dunslane(dot)net>
Date: 2016-03-19 18:36:35 -0400

Remove dependency on psed for MSVC builds.

Modern Perl has removed psed from its core distribution, so it might not
be readily available on some build platforms. We therefore replace its
use with a Perl script generated by s2p, which is equivalent to the sed
script. The latter is retained for non-MSVC builds to avoid creating a
new hard dependency on Perl for non-Windows tarball builds.

Backpatch to all live branches.

Michael Paquier and me.

Greetings,

Andres Freund