GraphicsBuffer can be used as an index buffer.
Allows a buffer to be used as an index buffer for Graphics.DrawProcedural and similar low level drawing APIs.
When you construct a GraphicsBuffer of this type, the value of stride must be either 2 (16-bit indices) or 4 (32-bit indices).
DirectX 11 does not allow Index buffers to also be Structured. For compute shader mesh data access with DirectX 11 compatibility, it is best to use Raw.
Additional resources: Graphics.RenderPrimitivesIndexed, Graphics.RenderPrimitivesIndexedIndirect, CommandBuffer.DrawProcedural, CommandBuffer.DrawProceduralIndirect,
Mesh.indexBufferTarget, Mesh.GetIndexBuffer.