update code based on feedback

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/DiffusionProfile/DiffusionProfileSettings.cs

             ValidateArray(ref halfRcpVariancesAndWeights, DiffusionProfileConstants.DIFFUSION_PROFILE_COUNT * 2);
             ValidateArray(ref filterKernelsBasic,         DiffusionProfileConstants.DIFFUSION_PROFILE_COUNT * DiffusionProfileConstants.SSS_BASIC_N_SAMPLES);
 
-            Debug.Assert(DiffusionProfileConstants.DIFFUSION_PROFILE_NEUTRAL_ID < 16, "Transmission flags (32-bit integer) cannot support more than 16 profiles (2 bits per profile).");
+            Debug.Assert(DiffusionProfileConstants.DIFFUSION_PROFILE_NEUTRAL_ID <= 16, "Transmission flags (32-bit integer) cannot support more than 16 profiles (2 bits per profile).");
 
             UpdateCache();
         }

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/Lit.hlsl

     bsdfData.bitangentWS    = cross(bsdfData.normalWS, bsdfData.tangentWS);
 }
 
-void FillMaterialIridescence(float thickness, inout BSDFData bsdfData)
+void FillMaterialIridescence(float thicknessIrid, inout BSDFData bsdfData)
-    bsdfData.thickness = thickness;
+    bsdfData.thicknessIrid = thicknessIrid;
 }
 
 // Note: this modify the parameter perceptualRoughness and fresnel0, so they need to be setup
         // We can reuse dist calculate in LS directly in WS as there is no scaling. Also the offset is already include in lightData.positionWS
         R = (positionWS + projectionDistance * R) - lightData.positionWS;
 
-        // Test again for clear code
+        // Test again for clear coat
         if (GPUImageBasedLightingType == GPUIMAGEBASEDLIGHTINGTYPE_REFLECTION && HasMaterialFeatureFlag(bsdfData.materialFeatures, MATERIALFEATUREFLAGS_LIT_CLEAR_COAT))
         {
             dirLS = mul(coatR, worldToLocal);
 
         // TODO: add distance based roughness
 
-        // Test again for clear code
+        // Test again for clear coat
         if (GPUImageBasedLightingType == GPUIMAGEBASEDLIGHTINGTYPE_REFLECTION && HasMaterialFeatureFlag(bsdfData.materialFeatures, MATERIALFEATUREFLAGS_LIT_CLEAR_COAT))
         {
             dirLS = mul(coatR, worldToLocal);