OpenGL CTS 4.6.0.1 Fixes: * Fix glTransformFeedbackBufferRange defintion * Move khr_debug tests to NoContext * Fixes for sparse texture clamp tests. * SparseTextureAlloc check for GL_NV_deep_texture3D * Fix ClearOpsBufferStorageTestCase on ppc64le * Fix XCreateWindow BadMatch with depth 32 visuals * Fix checks for maximum number of samples * Loosen color target tolerances for some tests * Remove use of unsupported SURFACETYPE_OFFSCREEN_GENERIC * Implementations can use more samples than requested * Remove read value check against uncommitted pages * Add some missing GL_TEXTURE_SPARSE state setting * Fix typo in log message for ClearOpsBufferStorage * Validate instancing cases properly