While msys2 itself may be x86_64 running emulated, it still does
indicate whether the host machine runs ARM64 (since recent
changes in https://github.com/msys2/msys2-runtime/pull/244 and
https://github.com/msys2/msys2-runtime/pull/245).
The msys2 uname command also exposes the Windows build number,
which allows determining whether armv7 and/or x86_64 binaries
can be executed.