[llvm] [CI] Refactor common functionality into separate script (PR #119530)

[Aiden Grossman via llvm-commits]

boomanaiden154 wrote:

> Any big changes to the code are best done when the new system is stable anyway.

Agreed. I'm trying to bring up the new system with minimal changes to the existing setup and then we can iterate from there once that is stable and we deprecate the old system.

> I wish those scripts were written in Python. But alas, not in the scope of this PR.

Yeah, I'm not the biggest fan of bash scripts. Something easier to write unit/regression tests against would be particularly nice. We'll have to make some decently big changes once the new system is stable to better take advantage of Github Actions, so I expect some migration to take place with that work.

https://github.com/llvm/llvm-project/pull/119530