[gcc r13-1657] [Ada] Fix internal error on untagged record type with equality operator

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

https://gcc.gnu.org/g:6faa271f09f32b32a6f4e32e3964faadc8372907

commit r13-1657-g6faa271f09f32b32a6f4e32e3964faadc8372907
Author: Eric Botcazou <ebotcazou@adacore.com>
Date:   Fri Jul 1 10:47:36 2022 +0200

    [Ada] Fix internal error on untagged record type with equality operator
    
    After the binding interpretation issued under AI12-0413, a user-defined
    primitive equality operator of an untagged record type hides the predefined
    equality operator in an instantiation, but this does not apply if the
    instantiation appears in the same declarative region as the type and
    before the declaration of this user-defined operator.
    
    gcc/ada/
    
            * sem_res.adb (Resolve_Equality_Op): Make sure that the user-defined
            operator of an untagged record type is declared ahead of an instance
            before using it to resolve the equality operator in the instance.

Diff:
---
 gcc/ada/sem_res.adb | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/gcc/ada/sem_res.adb b/gcc/ada/sem_res.adb
index 44fc955de74..1412d94198c 100644
--- a/gcc/ada/sem_res.adb
+++ b/gcc/ada/sem_res.adb
@@ -8967,7 +8967,14 @@ package body Sem_Res is
                then
                   Eq := Get_User_Defined_Equality (T);
 
-                  if Present (Eq) then
+                  --  We need to make sure that the instance is not within the
+                  --  same declarative region as the type, or else that it lies
+                  --  after the declaration of the user-defined "=" operator.
+
+                  if Present (Eq)
+                    and then (not In_Same_Extended_Unit (Eq, N)
+                               or else Earlier_In_Extended_Unit (Eq, N))
+                  then
                      if Is_Abstract_Subprogram (Eq) then
                         Nondispatching_Call_To_Abstract_Operation (N, Eq);
                      else