Could not call Config.resolve in Scalajs

```
[info] Done compiling.
[info] Fast optimizing /bhc/target/scala-2.12/bhc-fastopt.js
[error] Referring to non-existent class java.util.IdentityHashMap
```

It looks use typeconfig lib to resolve hocon config. There is not IdentityHashMap exists in scala lib, can I find other way to resolve it?