[llvm] [PowerPC][JITLink] Support R_PPC64_GOT_PCREL34 (PR #68658)

[Vassil Vassilev via llvm-commits]

https://github.com/vgvassilev approved this pull request.

This looks good to me and our use case in https://github.com/cms-sw/cmssw/issues/41658. I'd wait for one more reviewer to approve it. @lhames ping.

https://github.com/llvm/llvm-project/pull/68658