Support Heaven 4.0 under GLonD3D12..

Hi, seeing Zink branch (https://gitlab.freedesktop.org/zmike/mesa/-/commits/zink-wip) mentioned at Phoronix (https://www.phoronix.com/scan.php?page=news_item&px=Zink-OpenGL-4.6-On-Vulkan) already supports GL4.6 and runs Heaven 4.0 benchmark without issues would be nice if GLonD3D12 supported running it.. finally tried running and upon benchmark launch from GUI and after all "loading" takes place and benchmark should start windows closes without signaling any error.. supposedly Heaven 4.0 requires only GL3.3 (using GL4.0 features if extensions available) to run so should run on GLonD3D12.. I mentioned I would test that on: https://gitlab.freedesktop.org/kusma/mesa/-/issues/54

running Linux version (which should be equivalent in regards to GL usage) found that in console I get info about extensions used:

Found required GL_ARB_map_buffer_range
Found required GL_ARB_vertex_array_object
Found required GL_ARB_draw_instanced
Found required GL_ARB_draw_elements_base_vertex
Found required GL_ARB_transform_feedback
Found required GL_ARB_half_float_vertex
Found required GL_ARB_half_float_pixel
Found required GL_ARB_framebuffer_object
Found required GL_ARB_texture_multisample
Found required GL_ARB_uniform_buffer_object
Found required GL_ARB_geometry_shader4
Found optional GL_ARB_blend_func_extended
Found optional GL_ARB_tessellation_shader
Found optional GL_ARB_shader_bit_encoding
Found optional GL_ARB_sample_shading
Found optional GL_ARB_compute_shader
Found optional GL_ARB_gpu_shader5
Found optional GL_EXT_texture_compression_s3tc
Found optional GL_ARB_texture_compression_rgtc

so basically seems all extensions printed as "required" should be exposed by GLonD3D12.. running a simple tool like glewinfo shows that GLonD3D12 even supporting GL3.3 currently doesn't expose: GL_ARB_geometry_shader4 and GL_ARB_transform_feedback (only GL_EXT_transform_feedback is exposed) extensions from that list.. so maybe this is the cause benchmark fails to run.. would be nice if GLonD3D12 devs get interested in fixing bugs allowing to run Heaven 4.0.. assuming Heaven 4.0 requires GL features that should be currently supported by GLonD3D12 already.. EDIT: I cloned this repo yesterday and I tried also even applying: kusma/mesa!276 (merged) that exposes optional GL_EXT_texture_compression_s3tc extension to see if it helped..

thanks..