HDRenderLoop: Fix some warning in compute shaders

Assets/ScriptableRenderLoop/HDRenderLoop/Lighting/TilePass/ClusteredUtils.hlsl

 float GetScaleFromBase(float base)
 {
     const float C = (float)(1 << g_iLog2NumClusters);
-    const float geomSeries = (1.0 - pow(base, C)) / (1 - base);     // geometric series: sum_k=0^{C-1} base^k
+    const float geomSeries = (1.0 - pow(abs(base), C)) / (1 - base);     // geometric series: sum_k=0^{C-1} base^k
     return geomSeries / (g_fFarPlane - g_fNearPlane);
 }
 

Assets/ScriptableRenderLoop/HDRenderLoop/Lighting/TilePass/Resources/lightlistbuild-bigtile.compute

 
 	lightOffs = 0;
 	GroupMemoryBarrierWithGroupSync();
-	for(int i=t; i<iNrCoarseLights; i+=NR_THREADS) if(lightsListLDS[i]<g_iNrVisibLights) InterlockedAdd(lightOffs, 1);
+    int i;
+	for(i=t; i<iNrCoarseLights; i+=NR_THREADS) if(lightsListLDS[i]<g_iNrVisibLights) InterlockedAdd(lightOffs, 1);
-	for(int i=t; i<(iNrCoarseLights+1); i+=NR_THREADS)
+	for(i=t; i<(iNrCoarseLights+1); i+=NR_THREADS)
 		g_vLightList[MAX_NR_BIGTILE_LIGHTS_PLUSONE*offs + i] = t==0 ? iNrCoarseLights : lightsListLDS[i-1];
 }
 
 	const int totNrEdgePairs = 12*nrFrustEdges;
 	for(int l=0; l<iNrCoarseLights; l++)
 	{
-		const int idxCoarse = lightsListLDS[l];
+		const uint idxCoarse = lightsListLDS[l];
 		[branch]if(idxCoarse<(uint) g_iNrVisibLights && g_vLightData[idxCoarse].lightType!=SPHERE_LIGHT)		// don't bother doing edge tests for sphere lights since these have camera aligned bboxes.
 		{
 			SFiniteLightBound lgtDat = g_data[idxCoarse];
 		GroupMemoryBarrierWithGroupSync();
 #endif
 }
-#endif
+#endif

Assets/ScriptableRenderLoop/HDRenderLoop/Lighting/TilePass/Resources/lightlistbuild-clustered.compute

 	{
 		uint2 uPixCrd = min( uint2(viTilLL.x+(idx&0xf), viTilLL.y+(idx>>4)), uint2(iWidth-1, iHeight-1) );
 #ifdef MSAA_ENABLED
-		for(int i=0; i<iNumSamplesMSAA; i++)
+		for(uint i=0; i<iNumSamplesMSAA; i++)
 		{
 		const float fDpth = FetchDepthMSAA(g_depth_tex, uPixCrd, i);
 #else
 void ClearAtomic(uint threadID : SV_GroupIndex, uint3 u3GroupID : SV_GroupID)
 {
 	g_LayeredSingleIdxBuffer[0]=0;
-}
+}

Assets/ScriptableRenderLoop/HDRenderLoop/Lighting/TilePass/Resources/lightlistbuild.compute

 	lightOffsSph = 0;
 
 	// make a copy of coarseList in prunedList.
-	for(int l=threadID; l<iNrCoarseLights; l+=NR_THREADS)
+    int l;
+	for(l=threadID; l<iNrCoarseLights; l+=NR_THREADS)
 		prunedList[l]=coarseList[l];
 
 #if !defined(SHADER_API_XBOXONE) && !defined(SHADER_API_PSSL)
 	float onePixDiagDist = GetOnePixDiagWorldDistAtDepthOne();
 	float halfTileSizeAtZDistOne = 8*onePixDiagDist;		// scale by half a tile
 	
-	for(int l=threadID; l<iNrCoarseLights; l+=NR_THREADS)
+	for(l=threadID; l<iNrCoarseLights; l+=NR_THREADS)
 	{
 		SFiniteLightBound lightData = g_data[coarseList[l]];
 	
 		if(uIndex<MAX_NR_COARSE_ENTRIES) prunedList[uIndex] = coarseList[t];		// we allow up to 64 pruned lights while stored in LDS.
 	}
 }
-#endif
+#endif