RFC: Add CI validation for PRs

[dpaoliello]

Currently there is no automated checking for this project (certainly my most recent PR didn't run against any checks nor does this project have any Actions set up). This puts the onus on the maintainers to validate manually that any incoming PR doesn't break project (either building or actual output).

My proposal is to add a GitHub Action that builds the project against the current supported version(s) of LLVM and runs the existing tests. The Action would run on Linux (probably Ubuntu, since that's what GitHub Actions supports), Mac OS and Windows.

I'm happy to do the work to get this setup, but I will need a Project Admin to create the actual GitHub Action.

[vtjnash]

That would be great. I am happy to enable that or get you access to turn it on. Actually, I believe it is already turned on, but just waiting for someone to add a configuration file to define tests

[dpaoliello]

@vtjnash Would it be possible to enable mozilla-actions/sccache-action as one of the permitted actions for the repo (https://github.com/JuliaHubOSS/llvm-cbe/settings/actions)?

[vtjnash]

Done

[dpaoliello]

Ugh, looks like the version number matters, can you please update it to: mozilla-actions/sccache-action@*

[vtjnash]

Done