[Ada] Spurious error on early call region of tagged type

[Ada] Spurious error on early call region of tagged type

This patch corrects the part of the access-before-elaboration mechanism which
ensures that the freeze node of a tagged type is within the early call region
of all its overriding bodies to ignore predefined primitives.

------------
-- Source --
------------

--  pack.ads

package Pack with SPARK_Mode is
   type Parent_Typ is tagged null record;
   procedure Prim (Obj : Parent_Typ);

   type Deriv_Typ is new Parent_Typ with private;
   overriding procedure Prim (Obj : Deriv_Typ);

private
   type Deriv_Typ is new Parent_Typ with null record;
end Pack;

-----------------
-- Compilation --
-----------------

$ gcc -c pack.ads

2018-05-21  Hristian Kirtchev  <kirtchev@adacore.com>

gcc/ada/

	* exp_cg.adb: Remove with and use clause for Exp_Disp.
	* exp_ch9.adb: Remove with and use clause for Exp_Disp.
	* exp_disp.adb (Is_Predefined_Dispatching_Operation): Moved to Sem_Util.
	(Is_Predefined_Interface_Primitive): Moved to Sem_Util.
	(Is_Predefined_Internal_Operation): Moved to Sem_Util.
	* exp_disp.ads (Is_Predefined_Dispatching_Operation): Moved to Sem_Util.
	(Is_Predefined_Interface_Primitive): Moved to Sem_Util.
	(Is_Predefined_Internal_Operation): Moved to Sem_Util.
	* exp_dist.adb: Remove with and use clause for Exp_Disp.
	* freeze.adb: Remove with and use clause for Exp_Disp.
	* sem_cat.adb: Remove with and use clause for Exp_Disp.
	* sem_ch6.adb: Remove with and use clause for Exp_Disp.
	* sem_ch12.adb: Remove with and use clause for Exp_Disp.
	* sem_elab.adb (Check_Overriding_Primitive): Do not process predefined
	primitives.
	* sem_util.adb: Remove with and use clause for Exp_Disp.
	(Is_Predefined_Dispatching_Operation): Moved from Exp_Disp.
	(Is_Predefined_Interface_Primitive): Moved from Exp_Disp.
	(Is_Predefined_Internal_Operation): Moved from Exp_Disp.
	* sem_util.ads (Is_Predefined_Dispatching_Operation): Moved from
	Exp_Disp.
	(Is_Predefined_Interface_Primitive): Moved from Exp_Disp.
	(Is_Predefined_Internal_Operation): Moved from Exp_Disp.

From-SVN: r260467