Nouveau + LLVMpipe Drivers Enable OpenCL Image Support

The interesting work continues pouring in for Mesa 20.3 as the Q4'2020 feature release to this open-source graphics stack... The latest excitement is on the "Clover" front for Gallium3D OpenCL.

The LLVMpipe software back-end and Nouveau NVC0 Gallium3D drivers now are advertising OpenCL image support! This is important for making use of OpenCL acceleration with programs like Darktable and LuxCore, among many other imaging type programs supporting OpenCL.

The lack of OpenCL images support has been one of the unfortunate limitations over the years for the Mesa OpenCL "Clover" stack even as Clover added OpenCL 1.2 support and working on OpenCL 3.0. But unfortunately for now the OpenCL images support hasn't been wired up for the Radeon code with AMD continuing to focus on their separate Radeon Open Compute (ROCm) stack instead, which does have image support.

In any case this merge with proper images support for LLVMpipe and Nouveau NVC0 is now in Mesa 20.3-devel.