Better align heap snapshots contents with debugger info.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 883d7896c57e91dc31a1990845fd96557532eb63..32649bde542405b7c56f6e82a959aeb951158945 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -1180,7 +1180,11 @@ String* JSObject::constructor_name() {
   if (map()->constructor()->IsJSFunction()) {
     JSFunction* constructor = JSFunction::cast(map()->constructor());
     String* name = String::cast(constructor->shared()->name());
-    return name->length() > 0 ? name : constructor->shared()->inferred_name();
+    if (name->length() > 0) return name;
+    String* inferred_name = constructor->shared()->inferred_name();
+    if (inferred_name->length() > 0) return inferred_name;
+    Object* proto = GetPrototype();
+    if (proto->IsJSObject()) return JSObject::cast(proto)->constructor_name();
   }
   // If the constructor is not present, return "Object".
   return Heap::Object_symbol();