5073b5fdfa
Proof: https://alive2.llvm.org/ce/z/U-G7yV Helps: https://github.com/rust-lang/rust/issues/72646 and https://github.com/rust-lang/rust/issues/122734 Rust compiler's current output: https://godbolt.org/z/7E3fET6Md IPSCCP can do this transform but it does not help the motivating issue since it runs only once early in the optimization pipeline. Reimplementing this in CVP folds the motivating issue into a simple `icmp eq` instruction. Fixes #130100