Rust actually already does this to some degree, using LLVM’s noalias annotations (after many years of exposing latent LLVM bugs and having to disable them). There’s more that can be done here, see e.g.

https://github.com/rust-lang/rust/issues/16515

There are also soundness issues around async/await:

https://github.com/rust-lang/rust/issues/63818

LLVM’s aliasing model isn’t really optimal for a language like Rust with very precise memory dependence information, but using anything else would mean making a whole new optimizer/backend from scratch.