Introduce {ConstantElementsPair} struct for type safety.

src/factory.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/factory.h"
 
 #include "src/accessors.h"
 #include "src/allocation-site-scopes.h"
 #include "src/ast/ast.h"
 #include "src/base/bits.h"
@@ skipping 111 matching lines @@
 
 Handle<ContextExtension> Factory::NewContextExtension(
     Handle<ScopeInfo> scope_info, Handle<Object> extension) {
   Handle<ContextExtension> result =
       Handle<ContextExtension>::cast(NewStruct(CONTEXT_EXTENSION_TYPE));
   result->set_scope_info(*scope_info);
   result->set_extension(*extension);
   return result;
 }
 
+Handle<ConstantElementsPair> Factory::NewConstantElementsPair(
+    ElementsKind elements_kind, Handle<FixedArrayBase> constant_values) {
+  Handle<ConstantElementsPair> result = Handle<ConstantElementsPair>::cast(
+      NewStruct(CONSTANT_ELEMENTS_PAIR_TYPE));
+  result->set_elements_kind(elements_kind);
+  result->set_constant_values(*constant_values);
+  return result;
+}
+
 Handle<Oddball> Factory::NewOddball(Handle<Map> map, const char* to_string,
                                     Handle<Object> to_number,
                                     const char* type_of, byte kind) {
   Handle<Oddball> oddball = New<Oddball>(map, OLD_SPACE);
   Oddball::Initialize(isolate(), oddball, to_string, to_number, type_of, kind);
   return oddball;
 }
 
 
 Handle<FixedArray> Factory::NewFixedArray(int size, PretenureFlag pretenure) {
@@ skipping 2617 matching lines @@
     Handle<AccessorInfo> prototype =
         Accessors::FunctionPrototypeInfo(isolate(), rw_attribs);
     AccessorConstantDescriptor d(Handle<Name>(Name::cast(prototype->name())),
                                  prototype, rw_attribs);
     map->AppendDescriptor(&d);
   }
 }
 
 }  // namespace internal
 }  // namespace v8