Repro steps:
1. Create an add node
2. Plug a Sample Texture 2D node into the top slot
3. Plug a Vertex ID node into the bottom slot
4. Plug the result into vertex position
Expected result: having a fragment exclusive node plugged into a slot should make other slots incompatible with vertex exclusive routes, and vice versa (after plugging the Sample Texture 2D node into one slot it should not be possible to plug a Vertex ID node into the other slot on the add node)
Actual result: it is allowed and causes the shader to fail to compile, due to having a fragment exclusive node plugged into the vertex stage