HDRenderLoop: Submit optimization from Rune on area lights

Assets/ScriptableRenderLoop/HDRenderLoop/Material/Lit/LitSurfaceData.hlsl

 #endif
 
     // TODO: think about using BC5
-    float3 vertexNormalWS = input.tangentToWorld[2].xyz;
+    float3 vertexNormalWS = normalize(input.tangentToWorld[2].xyz);
 
 #ifdef _NORMALMAP
     #ifdef _NORMALMAP_TANGENT_SPACE
     surfaceData.tangentWS = SAMPLE_LAYER_TEXTURE2D(ADD_IDX(_TangentMap), ADD_ZERO_IDX(sampler_TangentMap), ADD_IDX(layerTexCoord.base)).rgb;
 #endif
 #else
-    surfaceData.tangentWS = input.tangentToWorld[0].xyz;
+    surfaceData.tangentWS = normalize(input.tangentToWorld[0].xyz);
 #endif
     // TODO: Is there anything todo regarding flip normal but for the tangent ?
 

Assets/ScriptableRenderLoop/ShaderLibrary/AreaLighting.hlsl

     // Clamp to avoid artifacts. This particular constant gives the best results.
     cosTheta    = Clamp(cosTheta, -0.9999, 0.9999);
     float theta = FastACos(cosTheta);
-    float res   = cross(v1, v2).z * theta / sin(theta);
+    float res = cross(v1, v2).z * theta * rsqrt(1.0f - cosTheta * cosTheta); // optimization from * 1 / sin(theta)
 
     return res;
 }