[runtime] support new Proxy() instead of Proxy.create and install getPrototypeOf trap

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 052fc5147288277ce83293579553ac02d784aac8..0b87e0815d4d385720a1e3ae405978b11587c037 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -1194,16 +1194,20 @@ MaybeHandle<Object> Object::SetElement(Isolate* isolate, Handle<Object> object,
 }
 
 
-Handle<Object> Object::GetPrototype(Isolate* isolate, Handle<Object> obj) {
+MaybeHandle<Object> Object::GetPrototype(Isolate* isolate,
+                                         Handle<Object> receiver) {
   // We don't expect access checks to be needed on JSProxy objects.
-  DCHECK(!obj->IsAccessCheckNeeded() || obj->IsJSObject());
+  DCHECK(!receiver->IsAccessCheckNeeded() || receiver->IsJSObject());
   Handle<Context> context(isolate->context());
-  if (obj->IsAccessCheckNeeded() &&
-      !isolate->MayAccess(context, Handle<JSObject>::cast(obj))) {
+  if (receiver->IsAccessCheckNeeded() &&
+      !isolate->MayAccess(context, Handle<JSObject>::cast(receiver))) {
     return isolate->factory()->null_value();
   }
-
-  PrototypeIterator iter(isolate, obj, PrototypeIterator::START_AT_RECEIVER);
+  if (receiver->IsJSProxy()) {
+    return JSProxy::GetPrototype(Handle<JSProxy>::cast(receiver));
+  }
+  PrototypeIterator iter(isolate, receiver,
+                         PrototypeIterator::START_AT_RECEIVER);
   do {
     iter.AdvanceIgnoringProxies();
     if (PrototypeIterator::GetCurrent(iter)->IsJSProxy()) {
@@ -6404,6 +6408,12 @@ int JSFunction::NumberOfLiterals() {
 
 ACCESSORS(JSProxy, handler, Object, kHandlerOffset)
 ACCESSORS(JSProxy, hash, Object, kHashOffset)
+// TODO(@neis): transform this into a real object field.
+Object* JSProxy::target() const { return map()->prototype(); }
+void JSProxy::set_target(Object* value, WriteBarrierMode mode) {
+  map()->set_prototype(value, mode);
+}
+
 ACCESSORS(JSFunctionProxy, call_trap, JSReceiver, kCallTrapOffset)
 ACCESSORS(JSFunctionProxy, construct_trap, Object, kConstructTrapOffset)