[llvm] [Github] Add initial version of precommit checks (PR #80951)

[Aiden Grossman via llvm-commits]

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@@ -0,0 +1,47 @@
+name: "Precommit tests"
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boomanaiden154 wrote:

I'm planning on a separate file per OS. Github doesn't have native `runs-on` support for containers on Windows, so we'll have to run the docker commands explicitly. The container image would need to be different either way, which means we would at least need separate jobs. I'm hoping to make sure common parts are pulled out into something common, but the OSes are different (at least as exposed to GHA for the way I want to use it).

https://github.com/llvm/llvm-project/pull/80951