miracl/MIRACL ? reverse-engineered prompt

Build me this cryptography library so I can compile it and try a simple example on my machine.

I want the project to work cleanly from a fresh clone, with clear build steps for a typical desktop setup, and if anything is missing or broken, please fix it. Make sure the core arithmetic and ECC related pieces still build, and that at least one small demo program shows how to use the library for basic big number work and a simple public key style example. If there are docs or sample programs that help explain how to get started, wire those up so they are easy to find and run.

Please keep it portable and don’t break the existing C code, but feel free to improve the setup, warnings, and any obvious build issues. If you need current build details from the docs or examples, look them up and follow the project’s existing approach.