Merge pull request #133 from Unity-Technologies/Branch_FixDrawRendererCallingConv

Added back the "ref" modifiers to DrawRenderer APIs (needs C++ too)

Assets/BasicRenderLoopTutorial/BasicRenderLoop.cs

             var settings = new DrawRendererSettings(cull, camera, new ShaderPassName("BasicPass"));
             settings.sorting.flags = SortFlags.CommonOpaque;
             settings.inputFilter.SetQueuesOpaque();
-            context.DrawRenderers(settings);
+            context.DrawRenderers(ref settings);
 
             // Draw skybox
             context.DrawSkybox(camera);
             settings.inputFilter.SetQueuesTransparent();
-            context.DrawRenderers(settings);
+            context.DrawRenderers(ref settings);
 
             context.Submit();
         }

Assets/ScriptableRenderLoop/HDRenderPipeline/HDRenderPipeline.cs

                 sorting = { flags = SortFlags.CommonOpaque }
             };
             settings.inputFilter.SetQueuesOpaque();
-            renderContext.DrawRenderers(settings);
+            renderContext.DrawRenderers(ref settings);
         }
 
         void RenderTransparentRenderList(CullResults cull, Camera camera, ScriptableRenderContext renderContext, string passName, RendererConfiguration rendererConfiguration = 0)
                 sorting = { flags = SortFlags.CommonTransparent }
             };
             settings.inputFilter.SetQueuesTransparent();
-            renderContext.DrawRenderers(settings);
+            renderContext.DrawRenderers(ref settings);
         }
 
         void RenderDepthPrepass(CullResults cull, Camera camera, ScriptableRenderContext renderContext)

Assets/ScriptableRenderLoop/RenderPasses/ShadowRenderPass.cs

             commandBuffer.Dispose();
 
             // Render
-            loop.DrawShadows(settings);
+            loop.DrawShadows(ref settings);
         }
     }
 }

Assets/ScriptableRenderLoop/fptl/FptlLighting.cs

             //@TODO: need to get light probes + LPPV too?
             settings.inputFilter.SetQueuesOpaque();
             settings.rendererConfiguration = RendererConfiguration.PerObjectLightmaps | RendererConfiguration.PerObjectLightProbe;
-            loop.DrawRenderers(settings);
+            loop.DrawRenderers(ref settings);
         }
 
         void RenderForward(CullResults cull, Camera camera, ScriptableRenderContext loop, bool opaquesOnly)
             if (opaquesOnly) settings.inputFilter.SetQueuesOpaque();
             else settings.inputFilter.SetQueuesTransparent();
 
-            loop.DrawRenderers(settings);
+            loop.DrawRenderers(ref settings);
         }
 
         static void DepthOnlyForForwardOpaques(CullResults cull, Camera camera, ScriptableRenderContext loop)
                 sorting = { flags = SortFlags.CommonOpaque }
             };
             settings.inputFilter.SetQueuesOpaque();
-            loop.DrawRenderers(settings);
+            loop.DrawRenderers(ref settings);
         }
 
         bool usingFptl