automoc: workaround for ranlib warning breaks reproducible builds
In order to have at least one valid symbol, !7558 (merged) added a dummy function to the automoc-generated sources. However, the function name is derived from the full path, which makes the resulting binary content depend on the build location.
I'm not sure if it is a good idea to introduce random symbols into an object file in the first place. For reproducible builds, the hashed path should at least be relative to the project root dir.