[windows-11-arm] Pre-install msys2

[jeremyd2019]

Type of issue

• Error when running a workflow.
• Request for additional tools or software for an existing image.
• Request for a new image, Linux or Windows.
• Other

Describe the issue
MSYS2 is not installed in C:\msys64 as it is on other Windows images

To Reproduce
try using msys2/setup-msys2 action with release: false option.

Expected behavior
C:\msys64 exists and contains MSYS2

Additional context
I thought about using msys2/setup-msys2 with release: true and location: C:\, but the action checks for and errors out in that configuration because
'location' cannot be 'C:' because that contains the built-in MSYS2 installation in GitHub Actions environments. See option 'release', in order to use that installation: https://github.com/msys2/setup-msys2#release

[Kichura]

MSYS2 currently does not exist as an native ARM64 program and cannot be deployed to this image unfortunately.

[jeremyd2019]

It runs fine under emulation. And based on some of these other issues asking for native ARM64 variants of things instead of the x86_64 versions (like #85), it's apparently not an issue to install x86_64 things.

[jeremyd2019]

Actually, there is some bug going on with the Qt installer (msys2/msys2-installer#96), but the sfx is probably what you'd want to use anyway (it's what I've used on self-hosted Windows-on-arm64 runners as long as I've had to provide them for msys2 due to GitHub lacking them).

[jeremyd2019]

I think the better strategy would be to install only native binaries in base image and if anything is not available at the time it can be installed by the user as x86, but with explicit decision to do so as it carry some implications.

There are cases where x86_64 tools are currently necessary to build aarch64 binaries, particularly MSYS2. MSYS2 is a Cygwin fork specifically for providing UNIX tools necessary to build native win32 (mingw-w64) binaries of open-source packages that are frequently UNIX-first. The toolchain support is not there to even start to port Cygwin to native aarch64 (it relies on GNU-specific things that are not in LLVM or MSVC), but it's still a useful tool to then get a large number of native aarch64 open-source libraries and tools. https://packages.msys2.org/packages/?repo=clangarm64