[objects-printer] Print hash code if available

Change-Id: Id7e93baaf9a4991c26c73579754a3a03d3822f1e
Reviewed-on: https://chromium-review.googlesource.com/759408Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49246}

src/objects-printer.cc

@@ -491,6 +491,10 @@ static void JSObjectPrintHeader(std::ostream& os, JSObject* obj,
      << ElementsKindToString(obj->map()->elements_kind());
   if (obj->elements()->IsCowArray()) os << " (COW)";
   os << "]";
+  Object* hash = obj->GetHash();
+  if (hash->IsSmi()) {
+    os << "\n - hash = " << Brief(hash);
+  }
   if (obj->GetEmbedderFieldCount() > 0) {
     os << "\n - embedder fields: " << obj->GetEmbedderFieldCount();
   }