[gcc r12-4678] [Ada] Simplify detection of a parent interface equality

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

https://gcc.gnu.org/g:9e67eed1efd54d17e863159086048be673e9587e

commit r12-4678-g9e67eed1efd54d17e863159086048be673e9587e
Author: Piotr Trojanek <trojanek@adacore.com>
Date:   Fri Oct 8 14:45:51 2021 +0200

    [Ada] Simplify detection of a parent interface equality
    
    gcc/ada/
    
            * exp_ch3.adb (Predefined_Primitive_Bodies): Simplify detection
            of existing equality operator.

Diff:
---
 gcc/ada/exp_ch3.adb | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/gcc/ada/exp_ch3.adb b/gcc/ada/exp_ch3.adb
index e8d4326ab8d..00a6b6c630e 100644
--- a/gcc/ada/exp_ch3.adb
+++ b/gcc/ada/exp_ch3.adb
@@ -10972,16 +10972,13 @@ package body Exp_Ch3 is
          while Present (Prim) loop
             if Chars (Node (Prim)) = Name_Op_Eq
               and then not Is_Internal (Node (Prim))
-              and then Present (First_Entity (Node (Prim)))
 
               --  The predefined equality primitive must have exactly two
-              --  formals whose type is this tagged type
+              --  formals whose type is this tagged type.
 
-              and then Present (Last_Entity (Node (Prim)))
-              and then Next_Entity (First_Entity (Node (Prim)))
-                         = Last_Entity (Node (Prim))
-              and then Etype (First_Entity (Node (Prim))) = Tag_Typ
-              and then Etype (Last_Entity (Node (Prim))) = Tag_Typ
+              and then Number_Formals (Node (Prim)) = 2
+              and then Etype (First_Formal (Node (Prim))) = Tag_Typ
+              and then Etype (Last_Formal (Node (Prim))) = Tag_Typ
             then
                Eq_Needed := False;
                Eq_Name := No_Name;