> it doesn't actually need to implement a borrow checker

I was under the impression that Rust's lifetime and ownership system is not just used to ensure safety, but also for knowing where the compiler should insert deallocation code for dynamically allocated objects at the end of their lifetimes. Is that not the case? Does mrustc generate code that leaks memory, or is there enough information in the Rust source code to do precise deallocation even without a borrow checker?