[llvm] [SimplifyCFG] Fold `select` of equality comparison into switch predecessor (PR #79177)

[Antonio Frighetto via llvm-commits]

antoniofrighetto wrote:

Uhmm, I think the new constraints are overly restrictive as the optimizations in `bench/fmt/optimized` are not taking place anymore...

https://github.com/llvm/llvm-project/pull/79177