Core: Change _Marshall class inherit from Reference to Object

(cherry picked from commit 9e8e5ebdc74f535df395eaf5d8031002edfe5a10)

core/bind/core_bind.h

@@ -598,9 +598,9 @@ private:
 	bool _list_skip_hidden;
 };
 
-class _Marshalls : public Reference {
+class _Marshalls : public Object {
 
-	GDCLASS(_Marshalls, Reference);
+	GDCLASS(_Marshalls, Object);
 
 	static _Marshalls *singleton;
 

doc/classes/@GlobalScope.xml

@@ -50,7 +50,7 @@
 			The [JavaScript] singleton.
 			[b]Note:[/b] Only implemented on HTML5.
 		</member>
-		<member name="Marshalls" type="Reference" setter="" getter="">
+		<member name="Marshalls" type="Marshalls" setter="" getter="">
 			The [Marshalls] singleton.
 		</member>
 		<member name="NavigationMeshGenerator" type="EditorNavigationMeshGenerator" setter="" getter="">

doc/classes/Marshalls.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8" ?>
-<class name="Marshalls" inherits="Reference" version="3.2">
+<class name="Marshalls" inherits="Object" version="3.2">
 	<brief_description>
 		Data transformation (marshalling) and encoding helpers.
 	</brief_description>