replace usage of goto_instructiont::get/set_condition()

Author: kroening

src/analyses/invariant_propagation.cpp

@@ -270,6 +270,6 @@ void invariant_propagationt::simplify(goto_programt &goto_program)
     ::simplify(simplified_guard, ns);
 
     if(invariant_set.implies(simplified_guard).is_true())
-      i_it->set_condition(true_exprt());
+      i_it->condition_nonconst() = true_exprt();
   }
 }

src/goto-instrument/concurrency.cpp

@@ -112,9 +112,7 @@ void concurrency_instrumentationt::instrument(
     }
     else if(it->is_assume() || it->is_assert() || it->is_goto())
     {
-      exprt cond = it->get_condition();
-      instrument(cond);
-      it->set_condition(cond);
+      instrument(it->condition_nonconst());
     }
     else if(it->is_function_call())
     {

src/goto-programs/goto_convert.cpp

@@ -269,7 +269,7 @@ void goto_convertt::optimize_guarded_gotos(goto_programt &dest)
     if(it->get_target()->target_number == it_z->target_number)
     {
       it->set_target(it_goto_y->get_target());
-      it->set_condition(boolean_negate(it->get_condition()));
+      it->condition_nonconst() = boolean_negate(it->condition());
       it_goto_y->turn_into_skip();
     }
   }

src/goto-programs/goto_inline_class.cpp

@@ -282,9 +282,8 @@ void goto_inlinet::insert_function_body(
 
       if(instruction.has_condition())
       {
-        exprt c = instruction.get_condition();
-        replace_location(c, target->source_location);
-        instruction.set_condition(c);
+        replace_location(
+          instruction.condition_nonconst(), target->source_location);
       }
     }
   }