[llvm] [LoadStoreVectorizer] Postprocess and merge equivalence classes (PR #114501)

[Vyacheslav Klochkov via llvm-commits]

v-klochkov wrote:

> I just ran the code formatter. One more thing, could you please name the unnamed/numbered vregs in the test -- this should help with any changes in the future? Please rebase on top of `main` branch -- once the builbots pass, I will merge the change.

@michalpaszkowski, thank you! I re-based the patch, removed unnamed/numbered vregs, removed `undef`: 4bff74970fc7d80dd5d261770d026c58b4b9a22f

https://github.com/llvm/llvm-project/pull/114501