[llvm] ValueTracking: refactor recurrence-matching (NFC) (PR #109659)

[Ramkumar Ramachandra via llvm-commits]

artagnon wrote:

> As an aside, can you format your PR titles per the style guide ('[] <msg...>" as opposed to ": <msg...>")

Is it specified in the style guide? I looked it up, but couldn't find a guideline saying this. I've been doing this for all my patches to save one valuable character in the title: it's a habit I picked up while contributing to upstream git. FWIW, there are some commits in the project that horribly overflow in both the title and body.

https://github.com/llvm/llvm-project/pull/109659