[ic] Support data handlers that represent simple field stores.

src/lookup.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/lookup.h"
 
 #include "src/bootstrapper.h"
 #include "src/deoptimizer.h"
 #include "src/elements.h"
 #include "src/field-type.h"
@@ skipping 575 matching lines @@
     Handle<JSObject> holder = GetHolder<JSObject>();
     FieldIndex field_index = FieldIndex::ForDescriptor(holder->map(), number_);
     return JSObject::FastPropertyAt(holder, property_details_.representation(),
                                     field_index);
   } else {
     result = holder_->map()->instance_descriptors()->GetValue(number_);
   }
   return handle(result, isolate_);
 }
 
+int LookupIterator::GetFieldDescriptorIndex() const {
+  DCHECK(has_property_);
+  DCHECK(holder_->HasFastProperties());
+  DCHECK_EQ(v8::internal::DATA, property_details_.type());
+  return descriptor_number();
+}
 
 int LookupIterator::GetAccessorIndex() const {
   DCHECK(has_property_);
   DCHECK(holder_->HasFastProperties());
   DCHECK_EQ(v8::internal::ACCESSOR_CONSTANT, property_details_.type());
   return descriptor_number();
 }
 
 
 int LookupIterator::GetConstantIndex() const {
@@ skipping 224 matching lines @@
                                       : access_check_info->named_interceptor();
     if (interceptor) {
       return handle(InterceptorInfo::cast(interceptor), isolate_);
     }
   }
   return Handle<InterceptorInfo>();
 }
 
 }  // namespace internal
 }  // namespace v8