Added model ID inside the design.

src/base/abc/abc.h

@@ -193,6 +193,7 @@ struct Abc_Ntk_t_
     Abc_Lib_t *       pDesign;
     short             fHieVisited;   // flag to mark the visited network
     short             fHiePath;      // flag to mark the network on the path
+    int               Id;            // model ID
     // miscellaneous data members
     int               nTravIds;      // the unique traversal IDs of nodes
     Mem_Fixed_t *     pMmObj;        // memory manager for objects

src/base/abc/abcLib.c

@@ -174,6 +174,8 @@ int Abc_LibAddModel( Abc_Lib_t * pLib, Abc_Ntk_t * pNtk )
     if ( st_is_member( pLib->tModules, (char *)pNtk->pName ) )
         return 0;
     st_insert( pLib->tModules, (char *)pNtk->pName, (char *)pNtk );
+    assert( pNtk->Id == 0 );
+    pNtk->Id = Vec_PtrSize(pLib->vModules);
     Vec_PtrPush( pLib->vModules, pNtk );
     pNtk->pDesign = pLib;
     return 1;