[llvm] [IndVarSimplify] Fix `IndVarSimplify` to skip on unfolding predicates when the loop contains control convergence operations. (PR #165643)

[Steven Perron via llvm-commits]

https://github.com/s-perron commented:

I think the code change looks good. However, the tests could be clearer. When writing llmv-ir tests, you can start with something for a high-level language to generate the test to start, but you want to reduce the test to something more to the point. You want to make it obvious what the test is testing. I made some suggests on one of the tests. Do the same for both.

https://github.com/llvm/llvm-project/pull/165643