[ESnext] Implement Object spread

src/runtime/runtime-object.cc

Index: src/runtime/runtime-object.cc
diff --git a/src/runtime/runtime-object.cc b/src/runtime/runtime-object.cc
index 5c726bb7cf7ec911ecdea17982df00f645825b5b..6c88b1e13d9da40950a77cc95f81d6906a8a202e 100644
--- a/src/runtime/runtime-object.cc
+++ b/src/runtime/runtime-object.cc
@@ -766,6 +766,22 @@ RUNTIME_FUNCTION(Runtime_DefineGetterPropertyUnchecked) {
   return isolate->heap()->undefined_value();
 }
 
+RUNTIME_FUNCTION(Runtime_CopyDataProperties) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(JSObject, target, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, source, 1);
+
+  // 2. If source is undefined or null, let keys be an empty List.
+  if (source->IsUndefined(isolate) || source->IsNull(isolate)) {
+    return isolate->heap()->undefined_value();
+  }
+
+  MAYBE_RETURN(
+      JSReceiver::SetOrCopyDataProperties(isolate, target, source, false),
+      isolate->heap()->exception());
+  return isolate->heap()->undefined_value();
+}
 
 RUNTIME_FUNCTION(Runtime_DefineSetterPropertyUnchecked) {
   HandleScope scope(isolate);