[Ada] AI12-0194: Language-defined aspects and entry bodies

gcc/ada/

	* sem_prag.adb (Analyze_Pragma, Pragma_Max_Entry_Queue_Length):
	Refine error message to indicate that the pragma must apply to
	an entry declaration, not just an entry.

gcc/ada/sem_prag.adb

@@ -19452,7 +19452,8 @@ package body Sem_Prag is
             --  Otherwise the pragma is associated with an illegal construct
 
             else
-               Error_Pragma ("pragma % must apply to a protected entry");
+               Error_Pragma
+                 ("pragma % must apply to a protected entry declaration");
                return;
             end if;