[llvm] ValueTracking/test: increase recurrence coverage (PR #108836)

[Nikita Popov via llvm-commits]

https://github.com/nikic approved this pull request.

LGTM, but I didn't try to confirm that the tests are not present elsewhere (a way to do that is to comment out the relevant cases and run tests...)

https://github.com/llvm/llvm-project/pull/108836