The extensions newly supported by the RadeonSI Gallium3D code in mainline Git is OpenGL 4.0's GL_ARB_draw_indirect and OpenGL 4.3's GL_ARB_multi_draw_indirect. This work is just about the RadeonSI Gallium3D driver and not R600g. These extensions are also enabled for the Gallium3D Softpipe and LLVMpipe fallback drivers too, besides the Nouveau NVC0 and Intel i965 support too.
Also added hours ago was a Gallium3D workaround for Unigine Heaven 4.0 and Unigine Valley 1.0 to workaround poor Unigine code. LLVM 3.4.2 has also now been made a requirement when building the Radeon Gallium3D driver for obtaining the very latest fixes found in the AMD GPU LLVM back-end.
For R600g users, the latest code now supports the GL_ARB_texture_gather extension of OpenGL 4.0 on AMD Radeon HD 5000 "Evergreen" graphics cards and newer.
These latest open-source AMD Linux graphics driver improvements can be found in the upcoming Mesa 10.3 release late this summer.