Cosmetic cleanups

include/swift/Driver/DependencyGraph.h

@@ -231,6 +231,8 @@ public:
   /// ("depends") are not cleared; new dependencies are considered additive.
   ///
   /// If \p node has already been marked, only its outgoing edges are updated.
+  /// The third argument is ignored here, but must be present so that the same
+  /// call site can polymorphically call \ref experimental_dependencies::ModuleDepGraph::loadFromPath
   LoadResult loadFromPath(T node, StringRef path, DiagnosticEngine &) {
     return DependencyGraphImpl::loadFromPath(Traits::getAsVoidPointer(node),
                                              path);