Treat class field as special function (such as `type`)

In Factorio, all the API classes have a object_name field (not function!), which identifies their class name, much like type() does for base types. We're currently handling this with a plugin that rewrites this from obj.object_name to look like __object_name(obj) which is then tagged as "Lua.runtime.special": { "__object_name": "type" }, , to get it to work properly in type-tests, but it would be nice to be able to indicate that a class field "acts like type" in this way directly.

まず、obj.object_name から __object_name(obj) への既存の plugin rewrite と、Lua.runtime.special から type への mapping を確認します。type-tests がその mapping をどのように利用しているかを追跡し、その後、クラスフィールドを直接宣言した場合にも rewrite なしで同じ動作が維持されることを検証します。