[D-Machine]

I think the careful response to this is:

(1) There are compilers written in C in the training set

(2) LLMs demonstrably can near-perfectly memorize training-set inputs (see other comments here)

(3) LLMs are very good at translation tasks (natural language or code, e.g.: C to Rust)

I don't think this necessarily completely deflates the impressiveness of this accomplishment, but it does qualify it to some degree.