[Ada] Missing error on illegal initialization item

[Pierre-Marie de Rodat <derodat at adacore dot com>]

This patch modifies the analysis of pragma Initializes to detect an illegal
null initialization item.

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

--  remote.ads

package Remote is
   Y : Integer := 0;
end Remote;

--  pack.ads

with Remote;

package Pack
   with SPARK_Mode,
        Initializes => (null => Remote.Y)
is
   X : Integer := 0;
end Pack;

----------------------------
-- Compilation and output --
----------------------------

$ gcc -c pack.ads
pack.ads:5:25: initialization item must denote object or state

Tested on x86_64-pc-linux-gnu, committed on trunk

2017-12-15  Hristian Kirtchev  <kirtchev@adacore.com>

	* sem_prag.adb (Analyze_Initialization_Item): Remove the specialized
	processing for a null initialization item. Such an item is always
	illegal.

Attachment: difs
Description: Text document