Replace deprecated llvm::Optional methods
Replace deprecated llvm::Optional methods

Generated by applying -Wdeprecated-declarations fixes from clang.

These are removed in https://github.com/llvm/llvm-project/commit/4b6b248731b81deb471838ff79392993aeb6c621

PiperOrigin-RevId: 490730675

google-research/structured-additive-IR,google-research/structured-additive-IR