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

[Akash Banerjee via cfe-commits]

TIFitis wrote:

> Some comments inlined.

I've addressed these in the latest commit.

> Do we support non trivial constructors for reduction variables? Similarly, did we support user defined reductions? If either questions is answered with yes, do we keep that support?
> 
> We might need to ask Alexey.

I haven't removed any code logic or made alterations that would affect these AFAIK.
I'm not sure however if these were supported in the first place. If @alexey-bataev has any tests for them then I could try them out before and after the patch and post an update here.



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