Doc: provide a code example of QDirIterator's nameFilters parameter

Change-Id: I56f9251f17bab0f835979a5feadec1fa896c9d69
Pick-to: 5.15
Reviewed-by: Venugopal Shivashankar <Venugopal.Shivashankar@qt.io>

src/corelib/doc/snippets/code/src_corelib_io_qdiriterator.cpp

@@ -69,3 +69,7 @@ while (it.hasNext()) {
     qDebug() << f.fileName() << f.readAll().trimmed().toDouble() / 1000 << "MHz";
 }
 //! [1]
+
+//! [2]
+QDirIterator audioFileIt(audioPath, {"*.mp3", "*.wav"}, QDir::Files);
+//! [2]

src/corelib/io/qdiriterator.cpp

@@ -462,10 +462,15 @@ QDirIterator::QDirIterator(const QString &path, IteratorFlags flags)
     By default, \a flags is NoIteratorFlags, which provides the same behavior
     as QDir::entryList().
 
+    For example, the following iterator could be used to iterate over audio
+    files:
+
+    \snippet code/src_corelib_io_qdiriterator.cpp 2
+
     \note To list symlinks that point to non existing files, QDir::System must be
      passed to the flags.
 
-    \sa hasNext(), next(), IteratorFlags
+    \sa hasNext(), next(), IteratorFlags, QDir::setNameFilters()
 */
 QDirIterator::QDirIterator(const QString &path, const QStringList &nameFilters,
                            QDir::Filters filters, IteratorFlags flags)