Ah, actually I spoke too soon. The way TS compiles namespaces to nested IEFEs in JS confuses Closure Compiler's mangler, so all the `fb.Schema.Foo` references get mangled to different names. I remember figuring this out when I first turned on CC, and that's why we do the ugly `import * as Schema_` and `import Type = Schema_.org.apache.arrow.flatbuf.Type` nonsense everywhere. Ugh.