Move Object.assign implementation to C++

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index 17a593dadf8e45b239be44c48bac08161fa7bb0d..e46ad99a90a74ae6dc01e19325ca6d6740ac96f3 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -1078,6 +1078,9 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
   Handle<String> object_name = factory->Object_string();
   JSObject::AddProperty(
       global_object, object_name, isolate->object_function(), DONT_ENUM);
+  SimpleInstallFunction(isolate->object_function(),
+                        isolate->factory()->InternalizeUtf8String("assign"),
+                        Builtins::kObjectAssign, 2, false);
 
   Handle<JSObject> global(native_context()->global_object());