Start port of HDRP BigTile to XR

Adding support for stereo-ized matrices

ScriptableRenderPipeline/HDRenderPipeline/HDRP/HDStringConstants.cs

         public static readonly int _EnvLightIndexShift = Shader.PropertyToID("_EnvLightIndexShift");
         public static readonly int g_isOrthographic = Shader.PropertyToID("g_isOrthographic");
         public static readonly int g_iNrVisibLights = Shader.PropertyToID("g_iNrVisibLights");
+
+        public static readonly int g_mScrProjectionArr = Shader.PropertyToID("g_mScrProjectionArr");
+        public static readonly int g_mInvScrProjectionArr = Shader.PropertyToID("g_mInvScrProjectionArr");
+
         public static readonly int g_iLog2NumClusters = Shader.PropertyToID("g_iLog2NumClusters");
         public static readonly int g_screenSize = Shader.PropertyToID("g_screenSize");
         public static readonly int g_iNumSamplesMSAA = Shader.PropertyToID("g_iNumSamplesMSAA");

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Lighting/LightLoop/LightLoop.cs

                 cmd.SetComputeIntParam(buildPerBigTileLightListShader, HDShaderIDs._DecalIndexShift, m_lightList.lights.Count + m_lightList.envLights.Count);
                 cmd.SetComputeIntParam(buildPerBigTileLightListShader, HDShaderIDs.g_iNrVisibLights, m_lightCount);
 
-                cmd.SetComputeMatrixParam(buildPerBigTileLightListShader, HDShaderIDs.g_mScrProjection, projscrArr[0]);
-                cmd.SetComputeMatrixParam(buildPerBigTileLightListShader, HDShaderIDs.g_mInvScrProjection, invProjscrArr[0]);
+                //cmd.SetComputeMatrixParam(buildPerBigTileLightListShader, HDShaderIDs.g_mScrProjection, projscrArr[0]);
+                //cmd.SetComputeMatrixParam(buildPerBigTileLightListShader, HDShaderIDs.g_mInvScrProjection, invProjscrArr[0]);
+                cmd.SetComputeMatrixArrayParam(buildPerBigTileLightListShader, HDShaderIDs.g_mScrProjectionArr, projscrArr);
+                cmd.SetComputeMatrixArrayParam(buildPerBigTileLightListShader, HDShaderIDs.g_mInvScrProjectionArr, invProjscrArr);
 
                 cmd.SetComputeFloatParam(buildPerBigTileLightListShader, HDShaderIDs.g_fNearPlane, camera.nearClipPlane);
                 cmd.SetComputeFloatParam(buildPerBigTileLightListShader, HDShaderIDs.g_fFarPlane, camera.farClipPlane);
                 cmd.SetComputeBufferParam(buildPerBigTileLightListShader, s_GenListPerBigTileKernel, HDShaderIDs.g_data, s_ConvexBoundsBuffer);
-                cmd.DispatchCompute(buildPerBigTileLightListShader, s_GenListPerBigTileKernel, numBigTilesX, numBigTilesY, 1);
+
+                int tgZ = m_FrameSettings.enableStereo ? 2 : 1;
+                tgZ = 1;
+                //cmd.DispatchCompute(buildPerBigTileLightListShader, s_GenListPerBigTileKernel, numBigTilesX, numBigTilesY, 1);
+                cmd.DispatchCompute(buildPerBigTileLightListShader, s_GenListPerBigTileKernel, numBigTilesX, numBigTilesY, tgZ);
             }
 
             var numTilesX = GetNumTileFtplX(hdCamera);

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Lighting/LightLoop/lightlistbuild-bigtile.compute

 #pragma kernel BigTileLightListGen
 
+#pragma enable_d3d11_debug_symbols
+
 #include "CoreRP/ShaderLibrary/common.hlsl"
 #include "LightLoop.cs.hlsl"
 #include "LightingConvexHullUtils.hlsl"
 
 uniform int g_iNrVisibLights;
 uniform uint2 g_viDimensions;
-uniform float4x4 g_mInvScrProjection;
-uniform float4x4 g_mScrProjection;
+
+//uniform float4x4 g_mInvScrProjection;
+//uniform float4x4 g_mScrProjection;
+uniform float4x4 g_mInvScrProjectionArr[2];
+uniform float4x4 g_mScrProjectionArr[2];
+
 uniform float g_fNearPlane;
 uniform float g_fFarPlane;
 uniform uint g_isOrthographic;
 groupshared unsigned int lightsListLDS[MAX_NR_BIG_TILE_LIGHTS_PLUS_ONE];
 groupshared uint lightOffs;
 
+// TODO: Remove this function and g_mInvScrProjectionArr from constants.
+// Only usage of that constant.
+    float4x4 g_mInvScrProjection = g_mInvScrProjectionArr[0];
+
     // for perspective projection m22 is zero and m23 is +1/-1 (depends on left/right hand proj)
 	// however this function must also work for orthographic projection so we keep it like this.
     float m22 = g_mInvScrProjection[2].z, m23 = g_mInvScrProjection[2].w;
 
 float3 GetViewPosFromLinDepth(float2 v2ScrPos, float fLinDepth)
 {
+    float4x4 g_mScrProjection = g_mScrProjectionArr[0];
+
 	bool isOrthographic = g_isOrthographic!=0;
 	float fSx = g_mScrProjection[0].x;
 	float fSy = g_mScrProjection[1].y;
 
 float GetOnePixDiagWorldDistAtDepthOne()
 {
+    float4x4 g_mScrProjection = g_mScrProjectionArr[0];
+
 	float fSx = g_mScrProjection[0].x;
 	float fSy = g_mScrProjection[1].y;