Install ConstructNonConstructable as construct stub for non-constructables.

src/runtime/runtime-object.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/bootstrapper.h"
 #include "src/debug/debug.h"
 #include "src/isolate-inl.h"
@@ skipping 1024 matching lines @@
   return *result;
 }
 
 
 RUNTIME_FUNCTION(Runtime_NewObject) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 2);
   CONVERT_ARG_HANDLE_CHECKED(JSFunction, constructor, 0);
   CONVERT_ARG_HANDLE_CHECKED(JSReceiver, new_target, 1);
 
-  // TODO(verwaest): Make sure |constructor| is guaranteed to be a constructor.
-  if (!constructor->IsConstructor()) {
-    THROW_NEW_ERROR_RETURN_FAILURE(
-        isolate, NewTypeError(MessageTemplate::kNotConstructor, constructor));
-  }
+  DCHECK(constructor->IsConstructor());
 
   // If called through new, new.target can be:
   // - a subclass of constructor,
   // - a proxy wrapper around constructor, or
   // - the constructor itself.
   // If called through Reflect.construct, it's guaranteed to be a constructor by
   // REFLECT_CONSTRUCT_PREPARE.
   DCHECK(new_target->IsConstructor());
 
   return Runtime_NewObjectHelper(isolate, constructor, new_target,
@@ skipping 525 matching lines @@
 
 RUNTIME_FUNCTION(Runtime_ObjectDefineProperties) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 2);
   CONVERT_ARG_HANDLE_CHECKED(Object, o, 0);
   CONVERT_ARG_HANDLE_CHECKED(Object, properties, 1);
   return JSReceiver::DefineProperties(isolate, o, properties);
 }
 }  // namespace internal
 }  // namespace v8