llvm-latest/llvm-mingw ? reverse-engineered prompt

Build me a simple way to get this LLVM MinGW toolchain up and running from source.

I want to be able to clone the repo and run one command to build a working Windows cross compiler, with clear output and sensible defaults. If it makes sense, also make the Docker build path work cleanly, since this project looks like it can be built either locally or in a container.

Please make sure the build includes the LLVM based tools, Clang, LLD, the MinGW runtime pieces, and the extra headers and libraries this fork supports. I’d also like the README or build steps to be easy enough that someone with basic terminal knowledge can follow them without guessing.

If there are any missing dependencies or setup steps, add them in a straightforward way. Use the latest docs online if you need to check anything.