[llvm] [DSE] Update dereferenceable attributes when adjusting memintrinsic ptr (PR #125073)

[Nikita Popov via llvm-commits]

https://github.com/nikic commented:

This introduces one regression: https://llvm.godbolt.org/z/1EjrE9xM6

It's due to this check: https://github.com/llvm/llvm-project/blob/2bffa5bf7abd4fc7b84f14d029a97c49f4b61130/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp#L2213

We should be doing the check in IntersectAttrs mode.

https://github.com/llvm/llvm-project/pull/125073