fix t2318 on JDK 17

SethTisue · SethTisue · commit 954c5ab570b8 · 2021-09-29T15:21:32.000-06:00
fixes scala/scala-dev#790
diff --git a/test/files/run/t2318.scala b/test/files/run/t2318.scala
@@ -4,6 +4,7 @@ import java.security._
 
 import scala.language.reflectiveCalls
 
+@deprecated("", since="") // suppress warnings about SecurityManager, deprecated on JDK 17
 object Test {
   trait Bar { def bar: Unit }
 
