[OpenMP][NVPTX] Added forward declaration for atomic operations

Pretty similar to D95058, this patch added forward declaration for
CUDA atomic functions. We already have definitions with right mangled names in
internal CUDA headers so the forward declaration here can work properly.

Reviewed By: jdoerfert, JonChesterfield

Differential Revision: https://reviews.llvm.org/D95085

GitOrigin-RevId: 48c54f0f623407192e93dc884724a12826eeab4f
1 file changed