[gcc r13-838] [Ada] Fix illegal Ada in s-dwalin.adb

[Pierre-Marie de Rodat]

https://gcc.gnu.org/g:f55e8fd165c1ed1e1c12def08ddb5f4fc55dafbb

commit r13-838-gf55e8fd165c1ed1e1c12def08ddb5f4fc55dafbb
Author: Romain Beguet <beguet@adacore.com>
Date:   Mon Apr 25 15:57:25 2022 +0200

    [Ada] Fix illegal Ada in s-dwalin.adb
    
    Both the `System.Mmap` and `System.Object_Reader` packages are defining
    entities named `Offset` and they are both `use`d at the top of
    s-dwalin.adb.
    
    Therefore, the references to `Offset` throughout this file are
    ambiguous, and GNAT is supposed to complain. Since it does not for the
    moment, we fix the ambiguity by declaring a subtype `Offset` at the top
    of the file simply renames `System.Object_Reader.Offset`.
    
    gcc/ada/
    
            * libgnat/s-dwalin.adb: Add a subtype declaration to fix the
            ambiguity.

Diff:
---
 gcc/ada/libgnat/s-dwalin.adb | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/gcc/ada/libgnat/s-dwalin.adb b/gcc/ada/libgnat/s-dwalin.adb
index 5a0a2f6bf72..e1e55f31a8a 100644
--- a/gcc/ada/libgnat/s-dwalin.adb
+++ b/gcc/ada/libgnat/s-dwalin.adb
@@ -44,6 +44,8 @@ with System.Storage_Elements;  use System.Storage_Elements;
 
 package body System.Dwarf_Lines is
 
+   subtype Offset is Object_Reader.Offset;
+
    function Get_Load_Displacement (C : Dwarf_Context) return Storage_Offset;
    --  Return the displacement between the load address present in the binary
    --  and the run-time address at which it is loaded (i.e. non-zero for PIE).