[gcc r11-5417] [Ada] Avoid potentially repeated calls to Prefix in Eval_Slice

[Pierre-Marie de Rodat]

https://gcc.gnu.org/g:bc0c82e99485589937789888e4bd7275c236b3be

commit r11-5417-gbc0c82e99485589937789888e4bd7275c236b3be
Author: Piotr Trojanek <trojanek@adacore.com>
Date:   Tue Sep 29 12:40:39 2020 +0200

    [Ada] Avoid potentially repeated calls to Prefix in Eval_Slice
    
    gcc/ada/
    
            * sem_eval.adb (Eval_Slice): Refactor repeated calls to Prefix
            with a local constant (named just like in Resolve_Slice).

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

diff --git a/gcc/ada/sem_eval.adb b/gcc/ada/sem_eval.adb
index e453bc1676b..4dc524817b6 100644
--- a/gcc/ada/sem_eval.adb
+++ b/gcc/ada/sem_eval.adb
@@ -3944,6 +3944,7 @@ package body Sem_Eval is
 
    procedure Eval_Slice (N : Node_Id) is
       Drange : constant Node_Id := Discrete_Range (N);
+      Name   : constant Node_Id := Prefix (N);
 
    begin
       if Nkind (Drange) = N_Range then
@@ -3955,9 +3956,9 @@ package body Sem_Eval is
       --  the type of A, is redundant, the slice can be replaced with A, and
       --  this is worth a warning.
 
-      if Is_Entity_Name (Prefix (N)) then
+      if Is_Entity_Name (Name) then
          declare
-            E : constant Entity_Id := Entity (Prefix (N));
+            E : constant Entity_Id := Entity (Name);
             T : constant Entity_Id := Etype (E);
 
          begin