[es6] Perform the IsConstructor test in GetSuperConstructor.

src/compiler/js-operator.h

Index: src/compiler/js-operator.h
diff --git a/src/compiler/js-operator.h b/src/compiler/js-operator.h
index a8625e4b083ac25a3be00cdebbff62cfa623c609..3a1e3d19872dc622303c884eb051dae413954231 100644
--- a/src/compiler/js-operator.h
+++ b/src/compiler/js-operator.h
@@ -521,6 +521,8 @@ class V8_EXPORT_PRIVATE JSOperatorBuilder final
 
   const Operator* HasProperty();
 
+  const Operator* GetSuperConstructor();
+
   const Operator* LoadGlobal(const Handle<Name>& name,
                              const VectorSlotPair& feedback,
                              TypeofMode typeof_mode = NOT_INSIDE_TYPEOF);