Support for Windows on ARM (WinARM64)

Greetings,

since I am an outlander, I shall write quickly.😁

Recently I've downloaded the source files of OpenMW v0.49 RC3 and managed to compile them for WinARM64. Some minor adjustments were necessary though, which I'd like to discuss.

OpenMW version 0.49.0
Revision: fe047d98b1
Using default (English) font encoding.
OSG version: 3.6.5
SDL version: 2.30.11
OpenGL Vendor: Microsoft Corporation
OpenGL Renderer: D3D12 (Qualcomm(R) Adreno(TM) 685 GPU)
OpenGL Version: 4.1 (Compatibility Profile) Mesa 24.3.0-devel (git-370ac36d5d)

Assuming you are interested in introducing new platform support and there is time for adjustments before the final release of v0.49.

Why emulate when you can go native?🤠