Group module fields together in CoreLibrary

Author: eregon

src/main/java/org/truffleruby/core/CoreLibrary.java

@@ -192,13 +192,14 @@ public class CoreLibrary {
     private final DynamicObject ioClass;
     private final DynamicObject closedQueueErrorClass;
     private final DynamicObject warningModule;
+    private final DynamicObjectFactory digestFactory;
+    private final DynamicObject structClass;
 
     private final DynamicObject argv;
-    private final GlobalVariables globalVariables;
     private final DynamicObject mainObject;
     private final DynamicObject nil;
-    private final DynamicObjectFactory digestFactory;
-    private final DynamicObject structClass;
+
+    private final GlobalVariables globalVariables;
 
     private final FrameDescriptor emptyDescriptor;