Testing BPF arena

[iii-i]

I noticed that BPF arena tests don't run even on x86_64: https://github.com/kernel-patches/bpf/actions/runs/9764673062/job/26953830302.

  #3       arena_atomics:SKIP

I don't quite see why: if LLVM support was missing, then we would get SKIP:no ENABLE_ATOMICS_TESTS or no addr_space_cast support in clang. I also don't see arena in the DENYLIST, although if it were there, it would not have printed SKIP at all.

Is this intentional?

[anakryiko]

@iii-i I think it might be LLVM support missing, we just don't see the message because it's just a printf(), which is by default is hidden (unless you run test_progs -v)

[iii-i]

I see, thanks. Are there plans to add LLVM 19 runs? I might have missed some discussions, but if I remember correctly in the past the recommendation was to run the testsuite with LLVM master, which I'm still doing in my dev setup.