What is ScriptMapper and how do we refresh it's shader references?

We have been profiling our app recently and we noticed shaders being referenced that aren't used by any game object/material in the scene. Some shaders are not even in the project anymore.

We stumbled upon something called ScriptMapper, that is referencing around 530 shaders, and supposedly it's trying to preload them all! What exactly is ScriptMapper and how can we regenerate that list and fix the missing references? We only came upon ScriptMapper via clicking on an entry in the Profiler.

We are running into a ton of shader memory issues on mobile devices and we suspect this could really be the problem. Any help would be appreciated. Thanks!