LLVM 18 or 19 Support

[zlfn]

This project is currently based on LLVM 17, But do you have any plans to upgrade it to LLVM 18 or 19? Can I upgrade LLVM version of this project to LLVM 18? How can I do that? Should I first post PR to update the version to LLVM 18 and then provide the missing instructions? Or I should to contribute to LLVM 18's instructions first and then update the LLVM version?

For example, In LLVM 18, or disjoint introduced to LLVM.
This is for optimization pass, so we can simply replace it with or.

Can I make a contribution for this instruction before the project updates to LLVM 18?

[vtjnash]

Updates are always welcome. The version support policy is pretty much #60