[gcc r14-6002] ada: Ignore defered compile time errors without backend

[Marc Poulhi?s <dkm@gcc.gnu.org>]

https://gcc.gnu.org/g:ce5572d4b8b391657f050b783f0a65471cd36ad2

commit r14-6002-gce5572d4b8b391657f050b783f0a65471cd36ad2
Author: Viljar Indus <indus@adacore.com>
Date:   Thu Nov 16 14:51:13 2023 +0200

    ada: Ignore defered compile time errors without backend
    
    We defer some compile time warnings and errors until the
    backend has added the extra information needed. However
    it is not guaranteed that the backend has run by this point.
    Avoid checking these errors if the backend has not been activated
    and no code has been generated.
    
    gcc/ada/
    
            * sem_prag.adb (Validate_Compile_Time_Warning_Errors): Avoid
            checking compile time warnings and errors if backend has not been
            activated.

Diff:
---
 gcc/ada/sem_prag.adb | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/gcc/ada/sem_prag.adb b/gcc/ada/sem_prag.adb
index 02f6f29c8a8..bd1d9d3d59b 100644
--- a/gcc/ada/sem_prag.adb
+++ b/gcc/ada/sem_prag.adb
@@ -33972,6 +33972,16 @@ package body Sem_Prag is
    --  Start of processing for Validate_Compile_Time_Warning_Errors
 
    begin
+
+      --  These error/warning messages were deferred because they could not be
+      --  evaluated in the front-end and they needed additional information
+      --  from the back-end. There is no reason to run these checks again if
+      --  the back-end was not activated by this point.
+
+      if not Generating_Code then
+         return;
+      end if;
+
       Expander_Mode_Save_And_Set (False);
       In_Compile_Time_Warning_Or_Error := True;