[SwiftInterfaceParser] Parser can't handle the swift 'any' syntax

[stephen-hawley]

Swift has added the any as a requirement for existential protocols (ie, protocols with no associated types).
The reasoning being that when you declare a function like this:

public protocol Talkable {
    func talk () -> String
}
public func identity (a: Talkable) -> Talkable
{
    return a
}

You're forcing dynamic rather than static dispatch so you should have an indication that this has an associated cost.
Therefore, this function is an exact synonym to the previous:

public func identity (a: any Talkable) -> Talkable // error: Invalid redeclaration of 'identity(a:)'
{
    return a
}

Any can also be used with protocols with associated types, but oddly enough these two functions:

public func otherIdentity (a: any Equatable) -> any Equatable {
    return a
}
public func otherIdentity<T:Equatable> (a: T) -> T {
    return a
}

does not cause an error, so they're distinct functions.