[gcc r14-6694] ada: Add missing guard to previous change

[Marc Poulhi?s]

https://gcc.gnu.org/g:40cf86ef4a51438a4c08e5937e5cbc61c1c28ec2

commit r14-6694-g40cf86ef4a51438a4c08e5937e5cbc61c1c28ec2
Author: Eric Botcazou <ebotcazou@adacore.com>
Date:   Fri Nov 24 12:07:28 2023 +0100

    ada: Add missing guard to previous change
    
    Ancestor_Type is overloaded with Aggregate_Bounds on N_Aggregate nodes
    so its access needs to be guarded in Copy_Generic_Node.
    
    gcc/ada/
    
            * sem_ch12.adb (Copy_Generic_Node): Add guard for Ancestor_Type.

Diff:
---
 gcc/ada/sem_ch12.adb | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/gcc/ada/sem_ch12.adb b/gcc/ada/sem_ch12.adb
index 2b8436d7c18..bfb400f5642 100644
--- a/gcc/ada/sem_ch12.adb
+++ b/gcc/ada/sem_ch12.adb
@@ -8518,10 +8518,12 @@ package body Sem_Ch12 is
 
             --  Moreover, for a full aggregate, if the type is a derived tagged
             --  type and has a global ancestor, then also restore the full view
-            --  of this ancestor, and do so up to the root type.
+            --  of this ancestor and do so up to the root type. Beware that the
+            --  Ancestor_Type field is overloaded, so test that it's an entity.
 
             if Nkind (N) = N_Aggregate
               and then Present (Ancestor_Type (N))
+              and then Nkind (Ancestor_Type (N)) in N_Entity
             then
                declare
                   Root_Typ : constant Entity_Id :=