[llvm] [OMPIRBuilder] Don't discard the debug record from entry block. (PR #135161)

[Abid Qadeer via llvm-commits]

abidh wrote:

> Could you add a test so we do not regress in the future?

Hi @Meinersbur 

Thanks for taking a look. Although this change fixes a missing piece, there is currently no way to test it as `CodeExtractor` does not generate the debug info in the entry block. This is preparatory PR for the bigger changes I am working on to improve the debug info of the function generated by the CodeExtractor. The bigger PR will have the tests.

This piece was independent and self contained so I thought I will post it separately.

https://github.com/llvm/llvm-project/pull/135161