2d8106cb5a
Summary: The CUDA impelementation has long supported the `width` argument on its shuffle instrucitons, which makes it more difficult to replace those uses with this helper. This patch just correctly implements that for AMDGPU and NVPTX so it's equivalent to `__shfl_sync` in CUDA. This will ease porting. Fortunately these get optimized out correctly when passing in known widths.