Enables the Caching Shader Preprocessor (experimental).
The Caching Shader Preprocessor is a shader preprocessor that is optimized for fast compilation. It caches intermediate preprocessing data to speed up shader import and compilation in the Unity Editor.
The Caching Shader Preprocessor closely follows the C preprocessor standard, and also supports limited conditional #pragma selection.
When the Caching Shader Preprocessor is enabled, you can use the "Preprocess Only" checkbox in the Shader Inspector to view the preprocessed source for that shader, rather than the generated code.