Bug 274729 – Support using Ref for interfaces and buffer source types in IDL unions

• Status: NEW
• Component: Bindings

[Sam Weinig]

Part of 274114.

[Sam Weinig]

Pull request: https://github.com/WebKit/WebKit/pull/29126

[Radar WebKit Bug Importer]

<rdar://problem/129133440>

[Sam Weinig]

To do this, we really need to support Ref for interfaces in dictionaries first, as without that, a union in a dictionary like:

```
dictionary Foo {
    required (Node or double) bar;
}
```

will still fail to compile.

That is being tracked in 305410. Blocking this on that.

[Sam Weinig]

Extending to also cover typed array wrappers in unions.