Properly test internal headers

[miscco]

Currently we werent testing all potential fallbacks we are using because some of the intrinsics are just available everywhere. This obviously led to some bugs slip in that would break everthing that includes type_traits.

To prevent this from happening again, add a script that crawls all internal headers and ensures both that they are building on their own and that all fallbacks path are at least exercised

This addresses nvbug4433362

[miscco]

@gevtushenko @robertmaynard I believe I have implemented the internal header test functionality in CMAKE.

That said, while I see that the file is actually used and the target generated, it seems to never be compiled. thoughts?

[miscco]

@wmaxey I believe this supersedes #1099

[robertmaynard]

@gevtushenko @robertmaynard I believe I have implemented the internal header test functionality in CMAKE.

That said, while I see that the file is actually used and the target generated, it seems to never be compiled. thoughts?

Looking at https://github.com/NVIDIA/cccl/actions/runs/7542844478/job/20532768330?pr=1258 I see header tests are being compiled. So I think you resolved this issue?

[github-actions]

Backport failed for branch/2.3.x, because it was unable to cherry-pick the commit(s).

Please cherry-pick the changes locally.

git fetch origin branch/2.3.x
git worktree add -d .worktree/backport-1258-to-branch/2.3.x origin/branch/2.3.x
cd .worktree/backport-1258-to-branch/2.3.x
git checkout -b backport-1258-to-branch/2.3.x
ancref=$(git merge-base 6034056fa7c37b7244920b1eb653b35b5a945a80 345b08e3fbdc1c1500992638af43e056d65ffd8f)
git cherry-pick -x $ancref..345b08e3fbdc1c1500992638af43e056d65ffd8f