[COMMITTED] ada: Fix internal error on declare-expression in post-condition

[COMMITTED] ada: Fix internal error on declare-expression in post-condition

[Marc Poulhiès]

From: Eric Botcazou <ebotcazou@adacore.com>

It comes from an incorrect node sharing in the expanded tree.

gcc/ada/

	* sem_ch3.adb (Find_Type_Of_Object): Copy the object definition when
	building the subtype declaration in the case of a spec expression.

Tested on x86_64-pc-linux-gnu, committed on master.

---
 gcc/ada/sem_ch3.adb | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/gcc/ada/sem_ch3.adb b/gcc/ada/sem_ch3.adb
index 1ed590ba519..9e32dea5c02 100644
--- a/gcc/ada/sem_ch3.adb
+++ b/gcc/ada/sem_ch3.adb
@@ -18423,19 +18423,21 @@ package body Sem_Ch3 is
             Analyze (Subtype_Mark (Obj_Def));
 
             declare
-               Base_T : constant Entity_Id := Entity (Subtype_Mark (Obj_Def));
-               Decl   : constant Node_Id :=
+               Base_T  : constant Entity_Id := Entity (Subtype_Mark (Obj_Def));
+               New_Def : constant Node_Id   := New_Copy_Tree (Obj_Def);
+               Decl    : constant Node_Id   :=
                  Make_Subtype_Declaration (Sloc (P),
                    Defining_Identifier => T,
-                   Subtype_Indication  => Relocate_Node (Obj_Def));
+                   Subtype_Indication  => New_Def);
+
             begin
                Set_Etype  (T, Base_T);
                Mutate_Ekind  (T, Subtype_Kind (Ekind (Base_T)));
-               Set_Parent (T, Obj_Def);
+               Set_Parent (T, Decl);
                Set_Scope (T, Current_Scope);
 
                if Ekind (T) = E_Array_Subtype then
-                  Constrain_Array (T, Obj_Def, Related_Nod, T, 'P');
+                  Constrain_Array (T, New_Def, Related_Nod, T, 'P');
 
                elsif Ekind (T) = E_Record_Subtype then
                   Set_First_Entity (T, First_Entity (Base_T));
-- 
2.40.0