Apply clang format as proposed in T53211.
For details on usage and instructions for migrating branches
without conflicts, see:
https://wiki.blender.org/wiki/Tools/ClangFormat
Built-in shaders now use uniforms instead of legacy built-in matrices. So far I only hooked this up for new immediate mode.
We use the same matrix naming convention as OpenGL, but without the gl_ prefix, e.g. gl_ModelView becomes ModelView.
Right now it can skip the new matrix stack and use the legacy built-in matrices app-side. This will help us transition gradually from glMatrix functions to gpuMatrix functions.
Still some work to do in gpuBindMatrices. See TODO comments in gpu_matrix.c for specifics.