[es6] Perform the IsConstructor test in GetSuperConstructor.

src/builtins/builtins-object.cc

 // Copyright 2016 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/builtins/builtins.h"
 #include "src/builtins/builtins-utils.h"
 
 #include "src/code-factory.h"
 #include "src/property-descriptor.h"
 
@@ skipping 1000 matching lines @@
 void Builtins::Generate_InstanceOf(CodeStubAssembler* assembler) {
   typedef compiler::Node Node;
   typedef CompareDescriptor Descriptor;
   Node* object = assembler->Parameter(Descriptor::kLeft);
   Node* callable = assembler->Parameter(Descriptor::kRight);
   Node* context = assembler->Parameter(Descriptor::kContext);
 
   assembler->Return(assembler->InstanceOf(object, callable, context));
 }
 
+void Builtins::Generate_GetSuperConstructor(CodeStubAssembler* assembler) {

[caitp, 2016/11/22 23:42:03]

It looks like this should take a compiler::CodeAssemblerState* parameter, not a
CodeStubAssembler. Based on my read of other TFS stubs, you need to create the
assembler yourself, eg `CodeStubAssembler assembler(state);`

[Benedikt Meurer, 2016/11/23 04:51:00]

Jep, you'll probably hit this once you rebase.

+  typedef compiler::Node Node;
+  typedef TypeofDescriptor Descriptor;
+
+  Node* object = assembler->Parameter(Descriptor::kObject);

[caitp, 2016/11/22 23:30:34]

if `object` is an Smi, GetSuperConstructor() will either crash or do something
weird/undefined.

[Henrique Ferreiro, 2016/12/01 12:22:22]

Shouldn't I check that in CodeStubAssembler::GetSuperConstructor instead of
using a CSA_ASSERT?

[Benedikt Meurer, 2016/12/01 13:11:51]

Yep.

+  Node* context = assembler->Parameter(Descriptor::kContext);
+
+  assembler->Return(assembler->GetSuperConstructor(object, context));
+}
+
 }  // namespace internal
 }  // namespace v8