Support Windows on ARM64

[billti]

This is for issue #247 . Putting up for early review, but some testing on other platforms and a couple questions remain.

[billti]

(Looks like the CI has been failing for a couple days unrelated to my change)

[billti]

Actually I see in the runner image used for Windows (https://github.com/actions/runner-images/blob/win22/20250127.1/images/windows/Windows2022-Readme.md) that GCC is included. So I'll revert that change to using 'clang' on Windows, install that locally, and try again.

[billti]

With the latest couple of commits and with 'gcc' installed locally via MSYS2 (as per the Windows CI build server), all tests are passing and the wheel is building successfully on my machine!

I've updated the main.yml with what is hopefully the prerequisite magic.

[alexcrichton]

Thank you for this!

[alexcrichton]

CI failures here will get fixed in bytecodealliance/actions#15 (or so I'm hoping), so I'll take care of the CI bits for this in the near future.

[alexcrichton]

Ok I think that CI failure might be legitimate?

[billti]

Ugh. As well as platform.machine() not matching on arm64, looks like Windows has a different value to Linux/Mac for x64 as well (on Mac and Linux it's x86_64). Sigh...

C:\code>python -c "import platform;print(platform.system());print(platform.machine())"
Windows
AMD64

I've just realized that this is also going to hit the same problem we have in our qsharp project as well, in that until there are Windows ARM64 runners available in the CI/release pipelines, while you can cross-compiler for Windows ARM64 fine, you won't be able to run the tests. We decided to live without test coverage for Windows ARM64 in our pipelines (https://github.com/microsoft/qsharp/blob/main/.ado/publish.yml#L343) and spot check the releases manually until Windows ARM64 runners become available, but I'll leave it up to you if that's acceptable here.

I'll push a commit shortly that fixes x64 on Windows and removes Windows aarch64 from the pipeline until you comment on the test coverage question. Thanks!

[billti]

I noticed none of the tests run on arm64 for any platforms - so there was nothing to remove and it seems in line. CI is green now! As extra validation, I copied/installed the wheel from the CI build to my Windows ARM64 machine into a clean venv and ran a few of the scripts from under ./examples and they all run fine.

[alexcrichton]

Thanks for confirming!

And yeah we could probably set up and arm64 runner now that ubuntu-arm64 images exist on github actions, but alas I don't think there are windows arm64 images just yet...