nixman/mingw-builds ? reverse-engineered prompt

Build me a simple command line tool that helps me build MinGW W64 compilers for both 32 bit and 64 bit targets on Windows, or on Linux through Wine if needed.

I want it to work with MSYS2, download the required sources, apply any needed patches, and then run the build for either i686 or x86_64. It should let me choose a GCC version, exception model, thread model, languages to include, and whether to use things like LTO or a static build. If I just run it with a basic command, it should do a sensible default build and put the results and archives in a clear output folder.

Please make it easy to follow, with helpful messages, and include a way to fetch sources only, update sources, and run tests when available. If anything about the current setup or recommended docs has changed, look up the latest info online and use that.