Revert of [runtime] Replace global object link with native context link in all contexts.

src/contexts-inl.h

Index: src/contexts-inl.h
diff --git a/src/contexts-inl.h b/src/contexts-inl.h
index 67358a7a1dd3e2029fb6d9ccadaa7e437c4ebe47..437aacf4afb451a0d81931bc82de251e0951275e 100644
--- a/src/contexts-inl.h
+++ b/src/contexts-inl.h
@@ -65,15 +65,15 @@
 void Context::set_module(JSModule* module) { set(EXTENSION_INDEX, module); }
 
 
-Context* Context::native_context() {
-  Object* result = get(NATIVE_CONTEXT_INDEX);
-  DCHECK(IsBootstrappingOrNativeContext(this->GetIsolate(), result));
-  return reinterpret_cast<Context*>(result);
+JSGlobalObject* Context::global_object() {
+  Object* result = get(GLOBAL_OBJECT_INDEX);
+  DCHECK(IsBootstrappingOrGlobalObject(this->GetIsolate(), result));
+  return reinterpret_cast<JSGlobalObject*>(result);
 }
 
 
-void Context::set_native_context(Context* context) {
-  set(NATIVE_CONTEXT_INDEX, context);
+void Context::set_global_object(JSGlobalObject* object) {
+  set(GLOBAL_OBJECT_INDEX, object);
 }
 
 
@@ -120,8 +120,8 @@
 
 
 bool Context::HasSameSecurityTokenAs(Context* that) {
-  return this->native_context()->security_token() ==
-         that->native_context()->security_token();
+  return this->global_object()->native_context()->security_token() ==
+         that->global_object()->native_context()->security_token();
 }