[Ada] Support Ada 2022 null array aggregates

Add support for Ada 2022's "[]" null array aggregates (thanks to Ed
Schonberg for producing most of this patch).

gcc/ada/

	* erroutc.ads: Fix a single-character typo in a comment.
	* exp_aggr.adb: Fix a single-character typo in a comment.
	Replace several pairs of calls to Low_Bound and
	High_Bound (which do not handle an identifier that denotes a
	scalar subtype) with corresponding calls to Get_Index_Bounds
	(which does handle that case).
	* par-ch4.adb (P_Aggregate_Or_Paren_Expr): Set the
	Component_Associations attribute of a null array aggregate to
	New_List.
	* sem_aggr.ads: New visible function
	Is_Null_Array_Aggregate_High_Bound.
	* sem_aggr.adb (Is_Null_Array_Aggregate_High_Bound,
	Is_Null_Aggregate, Resolve_Null_Array_Aggregate): New functions.
	(Resolve_Aggregate): Recognize null array aggregates (using
	Is_Null_Aggregate) and, when one is recognized, resolve
	it (using Resolve_Null_Array_Aggregate).  Avoid calling
	Array_Aggr_Subtype for a null array aggregate; the needed
	subtype is built in Resolve_Null_Array_Aggregate. Do not
	incorrectly flag a null aggregate (after it is transformed by
	expansion) as being both positional and named.
	* sem_attr.adb (Eval_Attribute): Special treatment for null
	array aggregate high bounds to avoid incorrectly flagging
	something like Integer'Pred (Integer'First) as an illegal static
	expression.
	* sem_eval.adb (Out_Of_Range): Special treatment for null array
	aggregate high bounds to avoid incorrectly flagging something
	like Integer'Pred (Integer'First) as an illegal static
	expression.

1 files changed, 1 insertions, 0 deletions

diff --git a/gcc/ada/par-ch4.adb b/gcc/ada/par-ch4.adb
index e0f3ca9..4ab4dcb 100644
--- a/gcc/ada/par-ch4.adb
+++ b/gcc/ada/par-ch4.adb
@@ -1405,6 +1405,7 @@ package body Ch4 is
             Scan;   --  past ]
             Aggregate_Node := New_Node (N_Aggregate, Lparen_Sloc);
             Set_Expressions (Aggregate_Node, New_List);
+            Set_Component_Associations (Aggregate_Node, New_List);
             Set_Is_Homogeneous_Aggregate (Aggregate_Node);
             return Aggregate_Node;
          end if;