In theory yes, this could be problematic with alternative Rust implementations, but it works fine and many people are using it in this case. We can be sure LLVM

In theory yes, this could be problematic with alternative Rust implementations, but it works fine and many people are using it in this case. We can be sure LLVM and Cranelift codegen backends will be implementing the same binary ABI, because binary ABI decisions are made in the shared code.