CppTools: Remove last traces of CppEditorSupport

Superseded by commit

    commit 89bd4ee3c4
    C++: Base parsing on editor document instead of widget

Change-Id: Iffa6e47bddc0fa3de1eab9b65fe8f711520d2d7f
Reviewed-by: Christian Stenger <christian.stenger@digia.com>

src/plugins/cpptools/cppmodelmanager.cpp

@@ -934,7 +934,7 @@ void CppModelManager::GC()
     if (!d->m_enableGC)
         return;
 
-    // Collect files of CppEditorSupport and AbstractEditorSupport.
+    // Collect files of opened editors and editor supports (e.g. ui code model)
     QStringList filesInEditorSupports;
     foreach (const EditorDocumentHandle *cppEditor, cppEditors())
         filesInEditorSupports << cppEditor->filePath();