[llvm] [mlir] [Utils][mlir] Fix interaction between CodeExtractor and OpenMPIRBuilder (PR #145051)

[Sergio Afonso via llvm-commits]

skatrak wrote:

> Is there a reason that target has to be handled differently? If not, either target offload maintainers should fix this to conform with the existing design or we should have an RFC discussing dropping the delayed outlining (`OutlineInfo`) entirely so that outlining occurs in a consistent way.

I tracked down the discussion about this decision to the initial implementation of `target` support: [D147172](https://reviews.llvm.org/D147172#4244736). Perhaps @jsjodin could check if the original reasons to not use `OutlineInfo` are still applicable, after things have matured a bit.

https://github.com/llvm/llvm-project/pull/145051