[llvm] [NewGVN] Disable SelfLookup optimization to ensure termination (PR #82162)

[via llvm-commits]

ManuelJBrito wrote:

To support this optimization, we need to perform SCC leader invalidation, i.e., prevent the existence of cyclic dependencies induced by leaders. For now, I will disable this optimization.

https://github.com/llvm/llvm-project/pull/82162