[llvm] [LLVM][DebugInfo]Allow ExtraData field to be a node reference (PR #165023)

[Orlando Cazalet-Hyams via llvm-commits]

OCHyams wrote:

I am unfamiliar with numba-cuda, can you explain how the metadata node references will be used? An example could be useful

https://github.com/llvm/llvm-project/pull/165023