Cirrus-CI: add gcc12 task on main branch

[emaste]

Summary

We want to get GCC coverage via Cirrus-CI, but don't want to trigger
excessive runs across all forks and branches.

Sponsored by:   The FreeBSD Foundation

[emaste]

.cirrus.yml

36

I don't think there's any way to or these together (trigger_type: manual and only_if: $CIRRUS_BRANCH == 'main')

[jhb]

.cirrus.yml

36

I wonder if we can make the automatic ones only trigger for a specific repo via only_if?

[emaste]

.cirrus.yml

36

Ah, perhaps just only_if: $CIRRUS_REPO_FULL_NAME == 'freebsd/freebsd-src'
Presumably any branch in the official mirror is a fair candidate. Let me try.

[jhb]

As noted in IRC, I think it would be nice to apply the same only_if clause to other automatic jobs as well and provide duplicate manual jobs for those also that developers can request in their own fork.

[emaste]

In D40027#911593, @jhb wrote:

As noted in IRC, I think it would be nice to apply the same only_if clause to other automatic jobs as well and provide duplicate manual jobs for those also that developers can request in their own fork.

I generally agree, but I'd like to see if Fedor has some advice so that we don't have to duplicate everything twice.