Remove unused rename(expr, old_id, new_id)

There is rename_symbolt providing the same functionality, and it is
actually used and optimised.

cr https://code.amazon.com/reviews/CR-1629519

Author: tautschnig

src/util/rename.cpp

@@ -8,10 +8,9 @@ Author: Daniel Kroening, kroening@kroening.com
 
 #include "rename.h"
 
-#include <algorithm>
+#include <string>
 
 #include "symbol.h"
-#include "expr.h"
 #include "namespace.h"
 
 /// automated variable renaming
@@ -35,34 +34,3 @@ void get_new_name(irep_idt &new_name, const namespacet &ns)
 
   new_name=prefix+std::to_string(ns.get_max(prefix)+1);
 }
-
-/// automated variable renaming
-/// \par parameters: expression, old name, new name
-/// \return modifies the expression returns false iff something was renamed
-bool rename(exprt &expr, const irep_idt &old_name,
-            const irep_idt &new_name)
-{
-  bool result=true;
-
-  if(expr.id()==ID_symbol)
-  {
-    if(expr.get(ID_identifier)==old_name)
-    {
-      expr.set(ID_identifier, new_name);
-      result=false;
-    }
-  }
-  else
-  {
-    if(expr.id()==ID_address_of)
-    {
-      // TODO
-    }
-    else
-      Forall_operands(it, expr)
-        if(!rename(*it, old_name, new_name))
-          result=false;
-  }
-
-  return result;
-}

src/util/rename.h

@@ -26,10 +26,4 @@ void get_new_name(symbolt &symbol,
 void get_new_name(irep_idt &new_name,
                   const namespacet &ns);
 
-// true: did nothing
-// false: renamed something in the expression
-
-bool rename(exprt &expr, const irep_idt &old_name,
-            const irep_idt &new_name);
-
 #endif // CPROVER_UTIL_RENAME_H