[the8472]

> In order to translate C code to Rust code that missing information must be produced by someone or something.

If you don't go for preserving the formal semantics of C code and instead only require the test-suite to still pass after translation that can provide a lot of wiggle room for the translation. This is how oxidation projects often work in practice. Fuzzers can also help with generating additional test data to get good branch coverage.