Emacs on Windows 11 Arm64

I got myself an Asus Zenbook A16 and it has been a really great experience so far. Even though the x86 compatibility is really good, I've been build some of the software I use for ARM so it's all native.

I setup this repo https://github.com/azumafuji/emacs-windows-arm64 to build Emacs for Windows 11 Arm64. Right now it's just building the 31.1 release tag. I'm planning to setup a nightly branch to build the latest version on master, and I'll keep up to date on official releases.

The repo builds a portable zip and an installer for ARM. There is also a `native` version that is optimised for the X2 processor. It doesn't really make a significant performance difference so it will probably get removed.

It was all done with LLM support to build the scripts and build pipeline. No changes the Emacs code except for some patches from MSYS2. It's all in the README. Hope it's helpful for someone.

https://redd.it/1x0w6f2
@r_emacs