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

src/value-serializer.cc

Index: src/value-serializer.cc
diff --git a/src/value-serializer.cc b/src/value-serializer.cc
index 132b5adc533052a82bb047e45af99df521ae9c14..c757650d04f44cb0d0b0b3f657b007e929001d3e 100644
--- a/src/value-serializer.cc
+++ b/src/value-serializer.cc
@@ -1595,6 +1595,7 @@ static void CommitProperties(Handle<JSObject> object, Handle<Map> 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]);
   }
 }