Merge pull request #1184 from Unity-Technologies/backport/shadow-backports

Backport/shadow backports

ScriptableRenderPipeline/LightweightPipeline/LWRP/LightweightPipeline.cs

             // stereo functionality, we use the screen-space shadow map as the source (until we have
             // a better solution).
             // An alternative would be DrawProcedural, but that would require further changes in the shader.
+            cmd.SetRenderTarget(m_ScreenSpaceShadowMapRT);
+            cmd.ClearRenderTarget(true, true, Color.white);
             cmd.Blit(m_ScreenSpaceShadowMapRT, m_ScreenSpaceShadowMapRT, m_ScreenSpaceShadowsMaterial);
 
             StartStereoRendering(ref context, frameRenderingConfiguration);

ScriptableRenderPipeline/LightweightPipeline/LWRP/ShaderLibrary/Shadows.hlsl

     attenuation = SAMPLE_TEXTURE2D_SHADOW(_ShadowMap, sampler_ShadowMap, shadowCoord.xyz);
 #endif
 
-#if SHADER_HINT_NICE_QUALITY
-#endif
 
     // Shadow coords that fall out of the light frustum volume must always return attenuation 1.0
     return BEYOND_SHADOW_FAR(shadowCoord) ? 1.0 : attenuation;