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

src/objects-inl.h

 // Copyright 2012 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.
 //
 // Review notes:
 //
 // - The use of macros in these inline functions may seem superfluous
 // but it is absolutely needed to make sure gcc generates optimal
 // code. gcc is not happy when attempting to inline too deep.
 //
@@ skipping 728 matching lines @@
     if (filter & SKIP_SYMBOLS) return true;
     if (Symbol::cast(this)->is_private()) return true;
   } else {
     if (filter & SKIP_STRINGS) return true;
   }
   return false;
 }
 
 Handle<Object> Object::NewStorageFor(Isolate* isolate, Handle<Object> object,
                                      Representation representation) {
-  if (representation.IsSmi() && object->IsUninitialized(isolate)) {
-    return handle(Smi::kZero, isolate);
-  }
   if (!representation.IsDouble()) return object;
   double value;
   if (object->IsUninitialized(isolate)) {
-    value = 0;
+    value = bit_cast<double>(kHoleNanInt64);
   } else if (object->IsMutableHeapNumber()) {
     value = HeapNumber::cast(*object)->value();
   } else {
     value = object->Number();
   }
   return isolate->factory()->NewHeapNumber(value, MUTABLE);
 }
 
 Handle<Object> Object::WrapForRead(Isolate* isolate, Handle<Object> object,
                                    Representation representation) {
@@ skipping 7652 matching lines @@
 #undef WRITE_INT64_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 #undef NOBARRIER_READ_BYTE_FIELD
 #undef NOBARRIER_WRITE_BYTE_FIELD
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_OBJECTS_INL_H_