Minimal changes to support llvm-15

[bertmaher]

Inside Meta we're pushing to support llvm-15, so need some minor API changes.

The biggest difference since 11 is the move to opaque, untyped pointers; I've applied LLVMContext::setOpaquePointers(false) to work around this for now, and hopefully the move to MLIR will obviate this by the time LLVM 16 comes around.

[ptillet]

Is it ok to delay this until after the triton-mlir merge? triton-mlir uses LLVM-14 right now, and it still will at merge time. Then, one of the first thing that will be done after the merge will be to switch to LLVM ~HEAD

[bertmaher]

That sounds fine; we’ve got an internal patch stack for changes like this so we aren’t blocked, I just expected it might be useful upstream too 🙂

[alexander-shaposhnikov]

@ptillet , @Jokeren - to take advantage of this discussion - would there be any interest in a pull request with the changes required for opaque pointers? (if yes - I'm happy to send it (after some additional testing / cleanup)) (the changes should be fine for both LLVM-11 and LLVM-14 (to the best of my knowledge))

[Jokeren]

Might be helpful if the patch can contribute to trition-mlir directly, from my perspective.