[eslaught]

The point is that whenever you do "IR -> Instructions" you are opening the possibility for logic errors to become memory errors. E.g. emitting opcode 9 instead of opcode 8 might (on some system) allow an attacker to execute arbitrary code. And these sorts of bugs cannot be prevented by pure memory safety alone, once you have (intentionally) opened the door to writing executable memory. You would actually need a full theorem prover to check the correctness of your code for you (which obviously Rust does not provide).