[llvm] [Offload] Implement the remaining initial Offload API (PR #122106)

[Joseph Huber via llvm-commits]

jhuber6 wrote:

> @jhuber6 Thanks! I've pushed some small fixes. Would you mind landing this PR when you get a chance? I don't have write access. No new libraries or lit tests this time so hopefully won't be as much trouble as the last one.

I'll probably want to try testing it locally first. How do you test it?

https://github.com/llvm/llvm-project/pull/122106