mpl: make isLargeFlatCluster const

Signed-off-by: João Mai <jmai@precisioninno.com>

Author: joaomai

src/mpl/src/clusterEngine.cpp

@@ -1482,7 +1482,7 @@ void ClusteringEngine::updateSubTree(Cluster* parent)
   }
 }
 
-bool ClusteringEngine::isLargeFlatCluster(Cluster* cluster)
+bool ClusteringEngine::isLargeFlatCluster(const Cluster* cluster) const
 {
   return (cluster->getDbModules().empty()
           && (cluster->getLeafStdCells().size() > max_std_cell_

src/mpl/src/clusterEngine.h

@@ -202,7 +202,7 @@ class ClusteringEngine
   void createCluster(odb::dbModule* module, Cluster* parent);
   void createCluster(Cluster* parent);
   void updateSubTree(Cluster* parent);
-  bool isLargeFlatCluster(Cluster* cluster);
+  bool isLargeFlatCluster(const Cluster* cluster) const;
   void breakLargeFlatCluster(Cluster* parent);
   bool partitionerSolutionIsFullyUnbalanced(const std::vector<int>& solution,
                                             int num_other_cluster_vertices);