Merge pull request #1504 from akka/wip-2996-make-test-work-on-j9-ban

Make AkkaSpec getCallerName work on J9 #2996

akka-testkit/src/test/scala/akka/testkit/AkkaSpec.scala

@@ -42,7 +42,8 @@ object AkkaSpec {
   }
 
   def getCallerName(clazz: Class[_]): String = {
-    val s = Thread.currentThread.getStackTrace map (_.getClassName) drop 1 dropWhile (_ matches ".*AkkaSpec.?$")
+    val s = (Thread.currentThread.getStackTrace map (_.getClassName) drop 1)
+      .dropWhile(_ matches "(java.lang.Thread|.*AkkaSpec.?$)")
     val reduced = s.lastIndexWhere(_ == clazz.getName) match {
       case -1 ⇒ s
       case z  ⇒ s drop (z + 1)