[PlanarProbe] Include custom HLSL files with shader generator

ScriptableRenderPipeline/Core/CoreRP/Editor/ShaderGenerator/CSharpToHLSL.cs

 
                     writer.Write("\n#endif\n");
 
+                    var customFile = it.Key + ".custom.hlsl";
+                    if (File.Exists(customFile))
+                        writer.Write("#include \"{0}\"", Path.GetFileName(customFile));
                 }
             }
         }

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Lighting/LightDefinition.cs.hlsl

 
 
 #endif
+#include "LightDefinition.cs.custom.hlsl"

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Lighting/Lighting.hlsl

 #define HAS_LIGHTLOOP // Allow to not define LightLoop related function in Material.hlsl
 
 #include "../Lighting/LightDefinition.cs.hlsl"
-#include "../Lighting/LightDefinition.custom.hlsl"
 #include "../Lighting/LightUtilities.hlsl"
 
 #include "LightLoop/Shadow.hlsl"

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Lighting/Reflection/VolumeProjection.hlsl

 #define ENVMAP_FEATURE_INFLUENCENORMAL
 
 #include "../LightDefinition.cs.hlsl"
-#include "../LightDefinition.custom.hlsl"
 
 float3x3 WorldToProxySpace(EnvLightData lightData)
 {

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Lighting/LightDefinition.cs.custom.hlsl.meta

+fileFormatVersion: 2
+guid: 2b0128e05dbdac743bab6a5a11857910
+ShaderImporter:
+  externalObjects: {}
+  defaultTextures: []
+  nonModifiableTextures: []
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Lighting/LightDefinition.custom.hlsl.meta

-fileFormatVersion: 2
-guid: 3ad8aff9e108a5e40b19c2c89fe7a448
-ShaderImporter:
-  externalObjects: {}
-  defaultTextures: []
-  nonModifiableTextures: []
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: