Fix [[Prototype]] initialization process for each object creation

* remove duplicated initialization for [[Prototype]] internal slot
* initialize prototype value directly when each Object created
* each prototype candidate object should be first marked as prototype object
* setGlobalIntrinsicObject marks fixed structure and prototype for global object's intrinsic object initialization

Signed-off-by: HyukWoo Park <hyukwoo.park@samsung.com>

src/runtime/ScriptGeneratorFunctionObject.cpp

@@ -26,8 +26,7 @@ namespace Escargot {
 
 Object* ScriptGeneratorFunctionObject::createFunctionPrototypeObject(ExecutionState& state)
 {
-    Object* prototype = new Object(state);
-    prototype->setPrototype(state, state.context()->globalObject()->generatorPrototype());
+    Object* prototype = new Object(state, state.context()->globalObject()->generatorPrototype());
     return prototype;
 }