cbdc00f6e6
This is a follow-up of
75aec4703d
.
There, I updated the wrapper to only include llvm/ADT/Optional.h for
LLVM version below 16. But I missed updating some of the None references.
Found by our experimental rust + llvm at HEAD bot:
https://buildkite.com/llvm-project/rust-llvm-integrate-prototype/builds/15587#0185006b-e0af-49e5-8b06-280ed125ff0d/200-539