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

[Johannes Hostert via llvm-commits]

JoJoDeveloping wrote:

> setjmp / longjmp may have similar problems?

Probably not, because you can only jump "up the stack" which is like returning from multiple functions at once. And also allowing longjmp/unwinding breaks many of the optimizations (which is why LLVM must infer `nounwind` usually for things to apply).

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