[gcc r13-486] [Ada] Fix internal error on iterated array aggregate

[Pierre-Marie de Rodat <pmderodat@gcc.gnu.org>]

https://gcc.gnu.org/g:e4acb82e97f8043dcd5e6b91b7d3c05d7b478b45

commit r13-486-ge4acb82e97f8043dcd5e6b91b7d3c05d7b478b45
Author: Eric Botcazou <ebotcazou@adacore.com>
Date:   Thu Mar 10 00:31:11 2022 +0100

    [Ada] Fix internal error on iterated array aggregate
    
    The front-end drops the declaration of a temporary on the floor because
    Insert_Actions fails to climb up out of an N_Iterated_Component_Association
    when the temporary is created during the analysis of its Discrete_Choices.
    
    gcc/ada/
    
            * exp_util.adb (Insert_Actions) <N_Iterated_Component_Association>:
            Climb up out of the node if the actions come from Discrete_Choices.

Diff:
---
 gcc/ada/exp_util.adb | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/gcc/ada/exp_util.adb b/gcc/ada/exp_util.adb
index 4198ceaa5b3..d3fbc4bc644 100644
--- a/gcc/ada/exp_util.adb
+++ b/gcc/ada/exp_util.adb
@@ -7751,12 +7751,17 @@ package body Exp_Util is
 
                  --  We must not climb up out of an N_Iterated_xxx_Association
                  --  because the actions might contain references to the loop
-                 --  parameter. But it turns out that setting the Loop_Actions
-                 --  attribute in the case of an N_Component_Association
-                 --  when the attribute was not already set can lead to
-                 --  (as yet not understood) bugboxes (gcc failures that are
-                 --  presumably due to malformed trees). So we don't do that.
-
+                 --  parameter, except if we come from the Discrete_Choices of
+                 --  N_Iterated_Component_Association which cannot contain any.
+                 --  But it turns out that setting the Loop_Actions field in
+                 --  the case of an N_Component_Association when the field was
+                 --  not already set can lead to gigi assertion failures that
+                 --  are presumably due to malformed trees, so don't do that.
+
+                 and then (Nkind (P) /= N_Iterated_Component_Association
+                            or else not Is_List_Member (N)
+                            or else
+                              List_Containing (N) /= Discrete_Choices (P))
                  and then (Nkind (P) /= N_Component_Association
                             or else Present (Loop_Actions (P)))
                then