suppress Sonar warnings about auto-closeable DefinitionsTokenStream (#3784)

* suppress Sonar warnings about auto-closeable DefinitionsTokenStream

* add comments

Author: Vladimir Kotal

opengrok-indexer/src/main/java/org/opengrok/indexer/analysis/plain/PlainAnalyzer.java

@@ -200,8 +200,9 @@ public void analyze(Document doc, StreamSource src, Writer xrefOut) throws IOExc
         }
     }
 
-    private void tryAddingDefs(Document doc, Definitions defs, StreamSource src)
-            throws IOException {
+    // DefinitionsTokenStream should not be used in try-with-resources
+    @SuppressWarnings("java:S2095")
+    private void tryAddingDefs(Document doc, Definitions defs, StreamSource src) throws IOException {
 
         DefinitionsTokenStream defstream = new DefinitionsTokenStream();
         defstream.initialize(defs, src, this::wrapReader);

opengrok-indexer/src/test/java/org/opengrok/indexer/analysis/plain/DefinitionsTokenStreamTest.java

@@ -18,6 +18,7 @@
  */
 
 /*
+ * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2018, Chris Fraire <[email protected]>.
  */
 package org.opengrok.indexer.analysis.plain;
@@ -97,6 +98,8 @@ public void testCppDefinitionsWithRawContent2() throws IOException {
             null);
     }
 
+    // DefinitionsTokenStream should not be used in try-with-resources
+    @SuppressWarnings("java:S2095")
     private void testDefinitionsVsContent(
             boolean expandTabs,
             String sourceResource,