I don’t know. there might already be. there is “normal” Windows support and there is various ARM support.
I would not be surprised if you didn’t have to do anything special right now. MSVC should just compile the code like nothing’s different. ARM is little-endian by default (but switchable), which is the same as x86-64. I don’t know if the OpenCL stuff needs work, probably not though. assembly code paths might need work.
I keep hearing about work on universal intrinsics and somesuch, in OpenCV. they do that to more easily support arbitrary platforms. this might directly benefit ARM Windows.
some somewhat historical links (from around 2022):