Pre-compile unity code

[ErikSchierboom]

Each exercise contains a test-framework directory with three files:

• unity.c
• unity.h
• unity_internals.h

See https://github.com/exercism/c/tree/main/exercises/practice/acronym/test-framework for an example.

As far as I can tell, these files are compiled for each test run. It would be great if we could pre-compiled these files with the Docker image, which would make running the tests quite a bit faster I think.

We've done the exact same thing for C++: exercism/cpp-test-runner#17

[wolf99]

I can look into this.
My usual caveat: the time I have to devote comes in random chunks; if someone else would also like to contribute this before I get finished, please do mention here and go ahead! 😄