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

[Nuno Lopes via llvm-commits]

nunoplopes wrote:

There are 3 failing tests in the build bots:
 - Transforms/NewGVN/pr32403.ll
 - Transforms/NewGVN/pr32838.ll
 - Transforms/NewGVN/pr32845.ll

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