Add stereo support to the light loop resolution-dependent buffers

Basically, use the 'screen' size for the tile gen, and then double if stereo exists

ScriptableRenderPipeline/HDRenderPipeline/HDRP/HDRenderPipeline.cs

                 if (m_CurrentWidth > 0 && m_CurrentHeight > 0)
                     m_LightLoop.ReleaseResolutionDependentBuffers();
 
-                m_LightLoop.AllocResolutionDependentBuffers(hdCamera.actualWidth, hdCamera.actualHeight);
+                m_LightLoop.AllocResolutionDependentBuffers((int)hdCamera.screenSize.x, (int)hdCamera.screenSize.y, m_FrameSettings.enableStereo);
             }
 
             // Warning: (resolutionChanged == false) if you open a new Editor tab of the same size!

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Lighting/LightLoop/LightLoop.cs

             return 8 * (1 << k_Log2NumClusters);       // total footprint for all layers of the tile (measured in light index entries)
         }
 
-        // TODO: Add proper stereo support
-        public void AllocResolutionDependentBuffers(int width, int height)
+        public void AllocResolutionDependentBuffers(int width, int height, bool stereoEnabled)
+            var nrStereoLayers = stereoEnabled ? 2 : 1;
+
-            var nrTiles = nrTilesX * nrTilesY;
+            var nrTiles = nrTilesX * nrTilesY * nrStereoLayers;
-            s_TileFeatureFlags = new ComputeBuffer(nrTilesX * nrTilesY, sizeof(uint));
+            s_TileFeatureFlags = new ComputeBuffer(nrTiles, sizeof(uint));
-                var nrClusterTiles = nrClustersX * nrClustersY;
+                var nrClusterTiles = nrClustersX * nrClustersY * nrStereoLayers;
 
                 s_PerVoxelOffset = new ComputeBuffer((int)LightCategory.Count * (1 << k_Log2NumClusters) * nrClusterTiles, sizeof(uint));
                 s_PerVoxelLightLists = new ComputeBuffer(NumLightIndicesPerClusteredTile() * nrClusterTiles, sizeof(uint));
             {
                 var nrBigTilesX = (width + 63) / 64;
                 var nrBigTilesY = (height + 63) / 64;
-                var nrBigTiles = nrBigTilesX * nrBigTilesY;
+                var nrBigTiles = nrBigTilesX * nrBigTilesY * nrStereoLayers;
                 s_BigTileLightList = new ComputeBuffer(LightDefinitions.s_MaxNrBigTileLightsPlusOne * nrBigTiles, sizeof(uint));
             }
         }