Looks like two AST changes in ocaml version didn't implement in the oxidized version.

1. v0.313.0 TypeParameter.bound is now a bare type node without the TypeAnnotation wrapper. https://github.com/facebook/flow/blob/HEAD/Changelog.md#03130
2. Unify enum body AST and move validation to type checker 9c81517

It's not clear for Prettier, which part of the logic should be kept.

Can you clearify? Thank you!