Don't double-allocate mutable heap numbers in the json parser. This removes some stupidity when com…

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 717a16a9cbe280125557d42d2191e967d18d5c5d..ebe4a2414b3b8ac721e6ee7f76efa126743eca02 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -4127,31 +4127,6 @@ bool JSObject::TryMigrateInstance(Handle<JSObject> object) {
 }
 
 
-void JSObject::WriteToField(int descriptor, Object* value) {
-  DisallowHeapAllocation no_gc;
-
-  DescriptorArray* desc = map()->instance_descriptors();
-  PropertyDetails details = desc->GetDetails(descriptor);
-
-  DCHECK(details.type() == DATA);
-
-  FieldIndex index = FieldIndex::ForDescriptor(map(), descriptor);
-  if (details.representation().IsDouble()) {
-    // Nothing more to be done.
-    if (value->IsUninitialized()) return;
-    if (IsUnboxedDoubleField(index)) {
-      RawFastDoublePropertyAtPut(index, value->Number());
-    } else {
-      HeapNumber* box = HeapNumber::cast(RawFastPropertyAt(index));
-      DCHECK(box->IsMutableHeapNumber());
-      box->set_value(value->Number());
-    }
-  } else {
-    RawFastPropertyAtPut(index, value);
-  }
-}
-
-
 void JSObject::AddProperty(Handle<JSObject> object, Handle<Name> name,
                            Handle<Object> value,
                            PropertyAttributes attributes) {