preprocessor: fix bug in adl implementation that prevented the same parameter from being applied do different endogenosu variables

SymbolTable.cc

@@ -657,10 +657,16 @@ SymbolTable::addAdlParameter(const string &basename, int lag) throw (FrozenExcep
 
   try
     {
-      return addSymbol(varname.str(), eParameter);
+      int symb_id = addSymbol(varname.str(), eParameter);
+      adl_params.push_back(symb_id);
+      return symb_id;
     }
   catch (AlreadyDeclaredException &e)
     {
+      int symb_id = getID(varname.str());
+      if (find(adl_params.begin(), adl_params.end(), symb_id) != adl_params.end())
+        return symb_id;
+
       cerr << "ERROR: you should rename your variable called " << varname.str() << ", this name is internally used by Dynare" << endl;
       exit(EXIT_FAILURE);
     }

SymbolTable.hh

@@ -153,6 +153,9 @@ private:
   //! Stores the list of observed exogenous variables
   vector<int> varexobs;
 
+  //! Stores list of parameters declared in adl substitution
+  vector<int> adl_params;
+
 public:
   SymbolTable();
   //! Thrown when trying to access an unknown symbol (by name)