8076543: Add @modules as needed to the langtools tests

Reviewed-by: jjg, shurailine
diff --git a/langtools/test/tools/javac/doctree/positions/TestPosition.java b/langtools/test/tools/javac/doctree/positions/TestPosition.java
index 8d03c8d..143444c 100644
--- a/langtools/test/tools/javac/doctree/positions/TestPosition.java
+++ b/langtools/test/tools/javac/doctree/positions/TestPosition.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2010, 2015, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -25,6 +25,7 @@
  * @test
  * @bug 8008174
  * @summary proper source positions for doc comments
+ * @modules jdk.compiler
  * @build TestPosition
  * @compile/ref=TestPosition.out -processor TestPosition -proc:only TestPositionSource.java
  */