LibJS: Clarify Object (base class) construction somewhat

Divide the Object constructor into three variants:

- The regular one (takes an Object& prototype)
- One for use by GlobalObject
- One for use by objects without a prototype (e.g ObjectPrototype)

Libraries/LibJS/Runtime/NumberObject.cpp

@@ -39,7 +39,7 @@ NumberObject* NumberObject::create(GlobalObject& global_object, double value)
 }
 
 NumberObject::NumberObject(double value, Object& prototype)
-    : Object(&prototype)
+    : Object(prototype)
     , m_value(value)
 {
 }