Annotation alias has unclear error with class.together

[samdphillips]

This produces expansion time error, ?: annotation static information needed before completed in: name

annot.macro 'E': 'Int || C || D'

class.together:
  class C(c :: List.of(E))
  class D(d :: E)

This works though

annot.macro 'E': 'Int || C || D'

class.together:
  class C(c :: List.of(Int || C || D))
  class D(d :: E)