In various previous commits all the remaining usages of this file were removed (b1d7e8fcb1,b1d7e8fcb1,2afd946ba,b43e2168e3). Now this file is finally completely unused, which means we can remove it. The main reason why we don't want this file is that it heavily relied on the preprocessor and makes it hard to decentralize implementation details of individual nodes. Pull Request: https://projects.blender.org/blender/blender/pulls/132855