[llvm] [OpenMPOpt] Null generic-mode wrappers for SPMDized kernels (PR #207611)

[Robert Imschweiler via llvm-commits]

ro-i wrote:

yeah, before OpenMPOpt and the Generic->SPMD optimization, the wrapper isn't dead. And after, afaiu, __kmpc_parallel_60 gets inlined and the wrapper function address is stored to LDS.
I think, removing it directly in OpenMPOpt makes sense because here, we *know* that it's dead. There is no heuristic necessary because we're the ones who killed it :)

https://github.com/llvm/llvm-project/pull/207611