C Shim for `Defer` Statements: Can It Be Compiler Agnostic?

Saw this HN post yesterday: https://news.ycombinator.com/item?id=45422717

It sparked joy and some great discussions. I turned the idea into a tiny, compiler-agnostic header-only shim that provides defer-like semantics in C as a short-term workaround until the language (hopefully?) adds a defer statement - Yay! :)