[Ada] Do not emit error in Relaxed_RM_Semantics mode

2018-05-22  Arnaud Charlet  <charlet@adacore.com>

gcc/ada/

	* sem_ch8.adb (Check_Frozen_Renaming): Do not emit error in
	Relaxed_RM_Semantics mode.

From-SVN: r260523

gcc/ada/ChangeLog

 2018-05-22  Arnaud Charlet  <charlet@adacore.com>
 
+	* sem_ch8.adb (Check_Frozen_Renaming): Do not emit error in
+	Relaxed_RM_Semantics mode.
+
+2018-05-22  Arnaud Charlet  <charlet@adacore.com>
+
 	* comperr.adb (Delete_SCIL_Files): Take into account
 	N_Generic_Package_Renaming_Declaration.
 

gcc/ada/sem_ch8.adb

@@ -4322,7 +4322,10 @@ package body Sem_Ch8 is
                Analyze (B_Node);
             end if;
 
-            if Is_Intrinsic_Subprogram (Old_S) and then not In_Instance then
+            if Is_Intrinsic_Subprogram (Old_S)
+              and then not In_Instance
+              and then not Relaxed_RM_Semantics
+            then
                Error_Msg_N
                  ("subprogram used in renaming_as_body cannot be intrinsic",
                   Name (N));