[COMMITTED] ada: Ignore defered compile time errors without backend

[COMMITTED] ada: Ignore defered compile time errors without backend

[Marc Poulhiès]

From: Viljar Indus <indus@adacore.com>

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.

Tested on x86_64-pc-linux-gnu, committed on master.

---
 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;
 
-- 
2.42.0