qmake: Add accessor for file lists to QmakePriFile

Change-Id: I37f9f39eba3bae2376d5349ce597e29fca6cb21f
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/plugins/qmakeprojectmanager/qmakeparsernodes.cpp

@@ -291,6 +291,20 @@ void QmakePriFile::makeEmpty()
     m_children.clear();
 }
 
+QSet<FileName> QmakePriFile::files(const FileType &type) const
+{
+    return m_files.value(type);
+}
+
+bool QmakePriFile::buildsFile(const FileName &fn) const
+{
+    for (auto it = m_files.constBegin(); it != m_files.constEnd(); ++it) {
+        if (it.value().contains(fn))
+            return true;
+    }
+    return false;
+}
+
 QmakePriFile::~QmakePriFile()
 {
     watchFolders(QSet<QString>());