Add dtrace worker tag support

[stratakis]

No description provided.

[encukou]

This is how I'd do it. Maybe the branch logic could be elsewhere, but "dtrace is installed" is a feature of the worker, and I think tags are great for such features.

[encukou]

I generally want to move to using tags for configure options -- but mostly builder tags: e.g. having separate factories for Windows64PGONoGilTailcallBuild and all the other combinations of PGO/NoGil/Tailcall aren't a good use of subclassing.

Does that look like a good direction?

[stratakis]

I generally want to move to using tags for configure options -- but mostly builder tags: e.g. having separate factories for Windows64PGONoGilTailcallBuild and all the other combinations of PGO/NoGil/Tailcall aren't a good use of subclassing.

Does that look like a good direction?

For me it does sound that it;s a proper direction as it would reduce a lot of subclassing, given of course that an option to do extra customizations without much hassle will be there.