[llvm] [Offload] Introduce offload-tblgen and initial new API implementation (PR #108413)

[Joseph Huber via llvm-commits]

jhuber6 wrote:

> This is absolutely our (Codeplay) preference, but I'd got the impression that we'd decided against this as a group.

As far as I recall, that was the preference of everyone at AMD and the only ones in favor of what we have now were Johannes and the people on the RFC that didn't contribute to `libomptarget`.

https://github.com/llvm/llvm-project/pull/108413