Add Windows build instructions with MSYS2

.github/workflows/cmake-multi-platform.yml

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README.md

@@ -251,8 +251,24 @@ The project requires CMake 3.20 or later and Clang 18 or later to build. Since t
 
 Compilers other than Clang have not been tested and are not recommended, including for recompilation output. The project relies on compiler-specific intrinsics and techniques that may not function correctly on other compilers, and many optimization methods depend on Clang's code generation.
 
+### Linux
+
+**TODO**
+
+### Windows (Visual Studio)
+
 On Windows, you can use the clang-cl toolset and open the project in Visual Studio's CMake integration.
 
+### Windows (MSYS2)
+
+Alternatively, you can install [MSYS2](https://www.msys2.org/) and use the "MSYS2 CLANG64" environment to build the project.
+
+First, you need to install the necessary packages (`mingw-w64-clang-x86_64-cmake`, `mingw-w64-clang-x86_64-libc++`, `mingw-w64-clang-x86_64-clang` and `mingw-w64-x86_64-ninja`) with `pacman -S <package_name>`.
+
+Then, you can head into the cloned repo's directory (you can access your C drive by going into the `/c` folder inside of MSYS2), and execute the command `cmake -DCMAKE_BUILD_TYPE=Debug .`, which will generate a `build.ninja` file for the project.
+
+Finally, run the `ninja` command, and you should end up with compiled executables. Attempting to launch them will tell you about a missing `libc++.dll` file, which you can copy to your current folder with the `cp /clang64/bin/libc++.dll .` command.
+
 ## Special Thanks
 
-This project could not have been possible without the [Xenia](https://github.com/xenia-project/xenia) emulator, as many parts of the CPU code conversion process has been implemented by heavily referencing its PPC code translator. The project also uses code from [Xenia Canary](https://github.com/xenia-canary/xenia-canary) to patch XEX binaries.
+This project could not have been possible without the [Xenia](https://github.com/xenia-project/xenia) emulator, as many parts of the CPU code conversion process has been implemented by heavily referencing its PPC code translator. The project also uses code from [Xenia Canary](https://github.com/xenia-canary/xenia-canary) to patch XEX binaries.