[gcc r16-1311] ada: Add example in Current_Entity_In_Scope comment

[Marc Poulhies]

https://gcc.gnu.org/g:7ab63499ac8a0883a53fbc85e7868d5f72f42571

commit r16-1311-g7ab63499ac8a0883a53fbc85e7868d5f72f42571
Author: Ronan Desplanques <desplanques@adacore.com>
Date:   Mon Mar 3 12:03:02 2025 +0100

    ada: Add example in Current_Entity_In_Scope comment
    
    gcc/ada/ChangeLog:
    
            * sem_util.ads (Current_Entity_In_Scope): Add example in comment.

Diff:
---
 gcc/ada/sem_util.ads | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/gcc/ada/sem_util.ads b/gcc/ada/sem_util.ads
index 38e9676c5c4b..29dbae8073ef 100644
--- a/gcc/ada/sem_util.ads
+++ b/gcc/ada/sem_util.ads
@@ -619,7 +619,21 @@ package Sem_Util is
    --  Find whether there is a previous definition for name or identifier N in
    --  the current scope. Because declarations for a scope are not necessarily
    --  contiguous (e.g. for packages) the first entry on the visibility chain
-   --  for N is not necessarily in the current scope.
+   --  for N is not necessarily in the current scope. Take, for example:
+   --
+   --  package P is
+   --     X : constant := 13;
+   --
+   --     package Q is
+   --        X : constant := 67;
+   --     end Q;
+   --
+   --     Y : constant := X;
+   --  end P;
+   --
+   --  When the declaration of Y is analyzed, the first entry on the visibility
+   --  chain is the X equal to 67, but Current_Entity_In_Scope returns the X
+   --  equal to 13.
 
    function Current_Scope return Entity_Id;
    --  Get entity representing current scope