[clang] [llvm] [mlir] [OpenMP] Migrate GPU Reductions CodeGen from Clang to OMPIRBuilder (PR #80343)

[Jan Leyonberg via cfe-commits]

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

This looks good to me now. You can wait a few days before merging to let @jdoerfert look it over again.


https://github.com/llvm/llvm-project/pull/80343