
This adds an option (WITH_COMPILER_CCACHE) to build using Ccache if it's found. Makefiles-based, Ninja-based and Xcode generators are supported. Pass `-DWITH_COMPILER_CCACHE=ON` to cmake to enable Ccache. Utility option in GNUmakefile is also added: for e.g., `make ninja ccache`. Reviewed By: brecht, ankitm Differential Revision: https://developer.blender.org/D9665