[llvm] [BPF] Define set of BPF libcalls (PR #169537)

[Lucas Ste via llvm-commits]

LucasSte wrote:

Hey @arsenm, thanks a lot for your feedback. I'll implement your suggestions for now and revert https://github.com/llvm/llvm-project/pull/168442.

> For i128 division you need to add createExpandLargeDivRemPass to the pass pipeline; it's broken that this isn't in the default codegen pipeline.

I have tested that locally and found it to work. I'll create a separate PR for that.

> This sounds like it should have a separate triple, and designed ABI?

I believe that is starting to make sense, yes. I'll first fix the i128 operations in BPF, then I'll think about that.

https://github.com/llvm/llvm-project/pull/169537