Add GetProperty/GetElement to JSReceiver and use it where possible

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 9112702685a5a70c4821e22e764f29da967b5f62..cd47b5e62b0944d7fa7c12591de6b429721322a5 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -1053,6 +1053,13 @@ MaybeHandle<Object> Object::GetProperty(Handle<Object> object,
   return GetProperty(&it);
 }
 
+MaybeHandle<Object> JSReceiver::GetProperty(Handle<JSReceiver> receiver,
+                                            Handle<Name> name) {
+  LookupIterator it(receiver, name, receiver);
+  if (!it.IsFound()) return it.factory()->undefined_value();
+  return Object::GetProperty(&it);
+}
+
 MaybeHandle<Object> Object::GetElement(Isolate* isolate, Handle<Object> object,
                                        uint32_t index) {
   LookupIterator it(isolate, object, index);
@@ -1060,6 +1067,14 @@ MaybeHandle<Object> Object::GetElement(Isolate* isolate, Handle<Object> object,
   return GetProperty(&it);
 }
 
+MaybeHandle<Object> JSReceiver::GetElement(Isolate* isolate,
+                                           Handle<JSReceiver> receiver,
+                                           uint32_t index) {
+  LookupIterator it(isolate, receiver, index, receiver);
+  if (!it.IsFound()) return it.factory()->undefined_value();
+  return Object::GetProperty(&it);
+}
+
 Handle<Object> JSReceiver::GetDataProperty(Handle<JSReceiver> object,
                                            Handle<Name> name) {
   LookupIterator it(object, name, object,
@@ -1090,10 +1105,11 @@ MaybeHandle<Object> JSReceiver::GetPrototype(Isolate* isolate,
   return PrototypeIterator::GetCurrent(iter);
 }
 
-MaybeHandle<Object> Object::GetProperty(Isolate* isolate, Handle<Object> object,
-                                        const char* name) {
+MaybeHandle<Object> JSReceiver::GetProperty(Isolate* isolate,
+                                            Handle<JSReceiver> receiver,
+                                            const char* name) {
   Handle<String> str = isolate->factory()->InternalizeUtf8String(name);
-  return GetProperty(object, str);
+  return GetProperty(receiver, str);
 }