Debug: Print full NodeKey when pretty printing ModuleGraphNode

This is helpful when debugging multiple component issues.

compiler/GHC/Unit/Module/Graph.hs

@@ -100,7 +100,7 @@ moduleGraphNodeUnitId mgn =
 instance Outputable ModuleGraphNode where
   ppr = \case
     InstantiationNode _ iuid -> ppr iuid
-    ModuleNode nks ms -> ppr (ms_mnwib ms) <+> ppr nks
+    ModuleNode nks ms -> ppr (msKey ms) <+> ppr nks
     LinkNode uid _     -> text "LN:" <+> ppr uid
 
 instance Eq ModuleGraphNode where