[gcc r13-1631] [Ada] Fix spurious warning on unreferenced internal generic instance

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

https://gcc.gnu.org/g:4fc09105aa018aec5645e7b2e8d00bef9e2e620e

commit r13-1631-g4fc09105aa018aec5645e7b2e8d00bef9e2e620e
Author: Piotr Trojanek <trojanek@adacore.com>
Date:   Mon Jun 27 13:09:10 2022 +0200

    [Ada] Fix spurious warning on unreferenced internal generic instance
    
    This patch removes a spurious warning, saying that an internal entity of
    a generic formal package is unreferenced. The immediate cause of this
    warning is that the internal entity is explicitly flagged as coming from
    source.
    
    The explicit flagging was added decades ago to fix a missing
    cross-reference in the ALI file. Apparently these days the
    cross-references work fine without this flag.
    
    gcc/ada/
    
            * sem_ch12.adb (Analyze_Package_Instantiation): Remove dubious
            call to Set_Comes_From_Source.

Diff:
---
 gcc/ada/sem_ch12.adb | 1 -
 1 file changed, 1 deletion(-)

diff --git a/gcc/ada/sem_ch12.adb b/gcc/ada/sem_ch12.adb
index af8bbbe2f9e..c980d7bb0ce 100644
--- a/gcc/ada/sem_ch12.adb
+++ b/gcc/ada/sem_ch12.adb
@@ -4297,7 +4297,6 @@ package body Sem_Ch12 is
 
       if Nkind (N) = N_Package_Instantiation then
          Act_Decl_Id := New_Copy (Defining_Entity (N));
-         Set_Comes_From_Source (Act_Decl_Id, True);
 
          if Nkind (Defining_Unit_Name (N)) = N_Defining_Program_Unit_Name then
             Act_Decl_Name :=