[llvm] [IR] Add disjoint flag for Or instructions. (PR #72583)

[Florian Hahn via llvm-commits]

fhahn wrote:

> I can reduce a test case if needed, but the assertion failure seems fairly self explanatory.

It might be a separate issue to #74112, so if it would be possible to reduce a test case to check if it is indeed an `or disjoint` that's causing this, that would be helpful. In any case, we should support preserving the new `disjoint` flag, so I put up #74364

https://github.com/llvm/llvm-project/pull/72583