Bug regressed in https://github.com/Unity-Technologies/Graphics/pull/3360 according to Chris Tchou
Repro steps:
1. Use a project with shadergraph
2. Bring the attached hlsl file into the project
3. Make a shadergraph
4. Add a custom function node
5. Set the file to the attached hlsl file
6. Name the function "customfunc"
7. Observe the error on the custom function node
Expected result: the custom function looks for the "_float" version of the function
Actual result: the custom function's error indicates it can't find the "_half" version of the function despite the fact that the custom function's precision is float due to inheritance