[llvm] [llubi] Experimental support for noalias (PR #195808)

[Ralf Jung via llvm-commits]

RalfJung wrote:

That sounds very cool. :) Cc @JojoDeveloping (the author of the blog post you cite)

Since I am not familiar with the codebase and my C++ is extremely Rusty, I don't think I'll be able to review the code here. I wonder if it would make sense to take some of the Tree Borrows test cases from Miri, translate them to LLVM IR, and have those as llubi testcases? Or maybe that IR is too verbose to make a good testcase we'd actually want to keep in-tree, but at least one could those testcases in llubi to get confirmation that the UB is caught. If you are interested in that then I can give you a list of suitable testcases -- note that there will be examples where Miri reports UB but the generated LLVM IR has no UB, because Rust has more aliasing restrictions than we can encode via `noalias` attributes.

https://github.com/llvm/llvm-project/pull/195808