Replace std::sort() with std::stable_sort() to avoid cross-platform performance mismatch.

source/Lib/EncoderLib/EncAdaptiveLoopFilter.cpp

@@ -3562,7 +3562,7 @@ void EncAdaptiveLoopFilter::determineControlIdcValues(CodingStructure &cs, const
   {
     std::copy_n(curFilterEnabled, MAX_NUM_CC_ALF_FILTERS, filterEnabled);
 
-    std::sort(filterIdxCount, filterIdxCount + MAX_NUM_CC_ALF_FILTERS, compareCounts);
+    std::stable_sort(filterIdxCount, filterIdxCount + MAX_NUM_CC_ALF_FILTERS, compareCounts);
 
     int filterIdc = 1;
     ccAlfFilterCount = 0;

source/Lib/EncoderLib/EncCu.h

@@ -97,7 +97,7 @@ public:
   GeoComboCostList() {};
   ~GeoComboCostList() {};
   std::vector<GeoMergeCombo> list;
-  void sortByCost() { std::sort(list.begin(), list.end(), SmallerThanComboCost()); };
+  void sortByCost() { std::stable_sort(list.begin(), list.end(), SmallerThanComboCost()); };
 };
 struct SingleGeoMergeEntry
 {

source/Lib/EncoderLib/IntraSearch.cpp

@@ -5838,7 +5838,7 @@ bool IntraSearch::xSortISPCandList(double bestCostSoFar, double bestNonISPCost,
   m_ispCandListVer.clear();
 
   // we sort the normal intra modes according to their full RD costs
-  std::sort(m_regIntraRDListWithCosts.begin(), m_regIntraRDListWithCosts.end(), ModeInfoWithCost::compareModeInfoWithCost);
+  std::stable_sort(m_regIntraRDListWithCosts.begin(), m_regIntraRDListWithCosts.end(), ModeInfoWithCost::compareModeInfoWithCost);
 
   // we get the best angle from the regular intra list
   int bestNormalIntraAngle = -1;