[display] missing @:forwardStatics completion if underlying type is abstract

The following compiles, but `Value` does not appear in completion:

```haxe
class Main {
static function main() {
trace(Bar.Value); // compiles
Bar.
}
}

@:forwardStatics
abstract Bar(Foo) {}

abstract Foo(Int) {
public static inline final Value = 0;
}
```


Hover and such seems fine:


I'm guessing https://github.com/HaxeFoundation/haxe/commit/7353ce621f1957611160b685e55bce822470262f fixed this only in case the underlying type is a class?

Reproduce the completion failure with the provided Main, Bar, and Foo snippet, then inspect commit 7353ce621f1957611160b685e55bce822470262f. Compare how @:forwardStatics handles class and abstract underlying types; done means Bar. completion includes the forwarded static Value.

Written by the indexing model from the issue text.