This is where I believe strong typing (like, Haskell-strong or stronger) and functional programming in general will be a win. The confidence I have that my fixes are localised when fixing Haskell code is infinitely stronger than fixing even Java, not speak about C, code.
Haskell's type system would not easily prevent this bug. It's not good at numeric/logic issues like that. When people say "Haskell makes it impossible to write bugs" they mean "Haskell has enums" (ADTs).
Imo, formal methods like more expressive/stricter type systems are key to making LLM generated code successful. Of course models will get better, but trusting the output will become much easier with a type system that proves more properties.
Even Lean 4 strong typing
You haven't mentioned the dynamic typed languages that I believe should die -- Python and Javascript. The only good use case for dynamic typing is notebooks (niche of R lang) where you're throwing out the code you just wrote after getting the result you wanted from it.