Implement a small optimization of the texture cache

ScriptableRenderPipeline/Core/TextureCache.cs

             var bFoundAvailOrExistingSlice = false;
 
             // search for existing copy
-            if (m_LocatorInSliceArray.ContainsKey(texId))
+            int cachedSlice;
+            if (m_LocatorInSliceArray.TryGetValue(texId, out cachedSlice))
-                sliceIndex = m_LocatorInSliceArray[texId];
+                sliceIndex = cachedSlice;
                 bFoundAvailOrExistingSlice = true;
                 Debug.Assert(m_SliceArray[sliceIndex].texId == texId);
             }

TestbedPipelines/Fptl/FptlLighting.cs

             var lightData = new SFiniteLightData[numVolumes];
             var boundData = new SFiniteLightBound[numVolumes];
             var worldToView = WorldToCamera(camera);
-            bool isNegDeterminant = Vector3.Dot(worldToView.GetColumn(0), Vector3.Cross(worldToView.GetColumn(1), worldToView.GetColumn(2))) < 0.0f;      // 3x3 Determinant.
 
             uint shadowLightIndex = 0;
             foreach (var cl in inputs.visibleLights)