[llvm] [offload] Extract OMPT out of PluginInterface (PR #221726)

[Jan André Reuter via llvm-commits]

Thyre wrote:

As mentioned by @jplehr, I'll do some testing on our side to see if the changes have any noticeable impact.
Due to some internal infrastructure changes, building a recent trunk commit and this PR might take a bit longer than I'd like.

While the changes look reasonable to me at first glance, I really want to make sure that we still receive correct event sequences, and that there's no impact on the reported device identifiers.



https://github.com/llvm/llvm-project/pull/221726