[crankshaft][runtime] Initialize uninitialized double fields with hole NaN value instead of 0.0.

src/value-serializer.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/value-serializer.h"
 
 #include <type_traits>
 
 #include "src/base/logging.h"
 #include "src/conversions.h"
@@ skipping 1577 matching lines @@
 // Copies a vector of property values into an object, given the map that should
 // be used.
 static void CommitProperties(Handle<JSObject> object, Handle<Map> map,
                              const std::vector<Handle<Object>>& properties) {
   JSObject::AllocateStorageForMap(object, map);
   DCHECK(!object->map()->is_dictionary_map());
 
   DisallowHeapAllocation no_gc;
   DescriptorArray* descriptors = object->map()->instance_descriptors();
   for (unsigned i = 0; i < properties.size(); i++) {
+    // Initializing store.
     object->WriteToField(i, descriptors->GetDetails(i), *properties[i]);
   }
 }
 
 Maybe<uint32_t> ValueDeserializer::ReadJSObjectProperties(
     Handle<JSObject> object, SerializationTag end_tag,
     bool can_use_transitions) {
   uint32_t num_properties = 0;
 
   // Fast path (following map transitions).
@@ skipping 263 matching lines @@
   if (stack.size() != 1) {
     isolate_->Throw(*isolate_->factory()->NewError(
         MessageTemplate::kDataCloneDeserializationError));
     return MaybeHandle<Object>();
   }
   return scope.CloseAndEscape(stack[0]);
 }
 
 }  // namespace internal
 }  // namespace v8