www/yarn: Converting HADOOPCOMPAT option in a FLAVOR

[pizzamig]

Summary

Converting the HADOOPCOMPAT option in a FLAVOR to make both packages available
I'm asking mat@ to review it, because it's the first FLAVOR use case I have.

Test Plan

Built both packages with poudriere

[mat]

This looks ok, but I am going to say no. For now, only ports with existing slave ports can be converted to flavors, so that the total numbers of packages does not grow.

[pizzamig]

My original idea was to add it a slave port, but then I've seen the work on FLAVORS and I preferred to wait FLAVORS be ready and use it.

[mat]

Well, please refrain from it right now.

There are a lot of cases where poudriere bulk -a goes beyond the 32k number of packages.
Poudriere uses tmpfs by default for its internal data, and up until recently in 12-CURRENT, tmpfs had a hard limit on 32k files per directory (or links, I don't remember).
So everyone who uses poudriere on 10 or 11 will get very strange errors.
Poudriere needs to grow a hashing feature of some sort, but it has not happened yet.

[pizzamig]

OK. I'll keep my patch waiting for better times, then.
BTW, thanks for the review