The new Function gets the inputs (types, number and order) and the output type of the dispatching Function, and the link to it. The user does not type these, so a mismatched signature cannot happen. This is better than a check after the user saves, because there is nothing to check.

How the link is stored depends on the decision in T440035.

Acceptance criteria

• A language-specific Function created from the entry point has the same inputs, in the same order, and the same output type as its dispatching Function, with no typing by the user.
• The link from the new Function to its dispatching Function and language is saved, in the form chosen in T440035.