remove 7 deprecated goto-program API methods

This removes 7 methods from the goto-program API that have been deprecated
since February, along with a few remaining uses.

Author: kroening

src/analyses/goto_check.cpp

@@ -2001,14 +2001,10 @@ void goto_checkt::goto_check(
                   expr.id() == ID_rw_ok;
          }))
       {
-        const exprt &rhs = i.get_assign().rhs();
+        const exprt &rhs = i.assign_rhs();
         auto rw_ok_cond = rw_ok_check(rhs);
         if(rw_ok_cond.has_value())
-        {
-          auto new_assign = i.get_assign(); // copy
-          new_assign.rhs() = *rw_ok_cond;
-          i.set_assign(new_assign);
-        }
+          i.assign_rhs_nonconst() = *rw_ok_cond;
       }
     }
     else if(i.is_function_call())

src/goto-instrument/contracts/contracts.cpp

@@ -816,7 +816,7 @@ void code_contractst::check_frame_conditions(
     if(instruction_it->is_decl())
     {
       // grab the declared symbol
-      const auto &decl_symbol = instruction_it->get_decl().symbol();
+      const auto &decl_symbol = instruction_it->decl_symbol();
       // move past the call and then insert the CAR
       instruction_it++;
       const auto car = assigns.add_to_write_set(decl_symbol);
@@ -838,7 +838,7 @@ void code_contractst::check_frame_conditions(
     }
     else if(instruction_it->is_dead())
     {
-      assigns.remove_from_write_set(instruction_it->get_dead().symbol());
+      assigns.remove_from_write_set(instruction_it->dead_symbol());
     }
     else if(
       instruction_it->is_other() &&

src/goto-programs/goto_program.h

@@ -229,26 +229,6 @@ class goto_programt
       return to_code_assign(code).rhs();
     }
 
-    /// Set the assignment for ASSIGN
-    DEPRECATED(SINCE(2021, 2, 24, "Use assign_lhs/rhs instead"))
-    void set_assign(code_assignt c)
-    {
-      PRECONDITION(is_assign());
-      code = std::move(c);
-    }
-
-    /// Get the declaration for DECL
-    DEPRECATED(SINCE(2021, 2, 24, "Use decl_symbol instead"))
-    const code_declt &get_decl() const
-    {
-      PRECONDITION(is_decl());
-      const auto &decl = expr_checked_cast<code_declt>(code);
-      INVARIANT(
-        !decl.initial_value(),
-        "code_declt in goto program may not contain initialization.");
-      return decl;
-    }
-
     /// Get the declared symbol for DECL
     const symbol_exprt &decl_symbol() const
     {
@@ -271,26 +251,6 @@ class goto_programt
       return decl.symbol();
     }
 
-    /// Set the declaration for DECL
-    DEPRECATED(SINCE(2021, 2, 24, "Use decl_symbol instead"))
-    void set_decl(code_declt c)
-    {
-      PRECONDITION(is_decl());
-      INVARIANT(
-        !c.initial_value(),
-        "Initialization must be separated from code_declt before adding to "
-        "goto_instructiont.");
-      code = std::move(c);
-    }
-
-    /// Get the dead statement for DEAD
-    DEPRECATED(SINCE(2021, 2, 24, "Use dead_symbol instead"))
-    const code_deadt &get_dead() const
-    {
-      PRECONDITION(is_dead());
-      return to_code_dead(code);
-    }
-
     /// Get the symbol for DEAD
     const symbol_exprt &dead_symbol() const
     {
@@ -305,22 +265,6 @@ class goto_programt
       return to_code_dead(code).symbol();
     }
 
-    /// Set the dead statement for DEAD
-    DEPRECATED(SINCE(2021, 2, 24, "Use dead_symbol instead"))
-    void set_dead(code_deadt c)
-    {
-      PRECONDITION(is_dead());
-      code = std::move(c);
-    }
-
-    /// Get the return statement for READ
-    DEPRECATED(SINCE(2021, 2, 24, "Use return_value instead"))
-    const code_returnt &get_return() const
-    {
-      PRECONDITION(is_set_return_value());
-      return to_code_return(code);
-    }
-
     /// Get the return value of a SET_RETURN_VALUE instruction
     const exprt &return_value() const
     {
@@ -335,14 +279,6 @@ class goto_programt
       return to_code_return(code).return_value();
     }
 
-    /// Set the return statement for SET_RETURN_VALUE
-    DEPRECATED(SINCE(2021, 2, 24, "Use return_value instead"))
-    void set_return(code_returnt c)
-    {
-      PRECONDITION(is_set_return_value());
-      code = std::move(c);
-    }
-
     /// Get the function call for FUNCTION_CALL
 #if 1
     DEPRECATED(SINCE(