sem_ch6.adb: Improve better error message.

2014-11-20  Ed Schonberg  <schonberg@adacore.com>

	* sem_ch6.adb: Improve better error message.

From-SVN: r217847

gcc/ada/ChangeLog

+2014-11-20  Ed Schonberg  <schonberg@adacore.com>
+
+	* sem_ch6.adb: Improve better error message.
+
 2014-11-20  Thomas Quinot  <quinot@adacore.com>
 
 	* freeze.adb, sem_ch13.adb: Minor editing.

gcc/ada/sem_ch6.adb

@@ -334,7 +334,8 @@ package body Sem_Ch6 is
            and then Nkind (Original_Node (Unit_Declaration_Node (Prev)))
              =  N_Expression_Function
          then
-            Error_Msg_N ("Duplicate expression function", N);
+            Error_Msg_Sloc := Sloc (Prev);
+            Error_Msg_N ("& conflicts with declaration#", Def_Id);
             return;
          end if;
       end if;