[gcc r16-1157] ada: Fix crash on access to protected return

[Marc Poulhies]

https://gcc.gnu.org/g:201fd7899da99767f88fbd75d61b20fdc0cc190d

commit r16-1157-g201fd7899da99767f88fbd75d61b20fdc0cc190d
Author: Ronan Desplanques <desplanques@adacore.com>
Date:   Mon Jan 27 12:04:41 2025 +0100

    ada: Fix crash on access to protected return
    
    The generation of the check mandated by Ada issue AI05-0073 was not done
    handled properly for protected types when used through subtypes. This
    patch fixes the issue.
    
    gcc/ada/ChangeLog:
    
            * exp_ch4.adb (Tagged_Membership): Fix for protected types.

Diff:
---
 gcc/ada/exp_ch4.adb | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/gcc/ada/exp_ch4.adb b/gcc/ada/exp_ch4.adb
index 8c724844eb32..eb9fb6bba569 100644
--- a/gcc/ada/exp_ch4.adb
+++ b/gcc/ada/exp_ch4.adb
@@ -15036,10 +15036,11 @@ package body Exp_Ch4 is
 
       --  Handle entities from the limited view
 
-      Orig_Right_Type : constant Entity_Id := Available_View (Etype (Right));
+      Orig_Right_Type : constant Entity_Id :=
+        Base_Type (Available_View (Etype (Right)));
 
       Full_R_Typ   : Entity_Id;
-      Left_Type    : Entity_Id := Available_View (Etype (Left));
+      Left_Type    : Entity_Id := Base_Type (Available_View (Etype (Left)));
       Right_Type   : Entity_Id := Orig_Right_Type;
       Obj_Tag      : Node_Id;