Incorrect handling of unbound generic types in open classes

[stephen-hawley]

open class Tester<T> {
	private var x: T?
	public init (a: T) {
		x = a
	}
	open func getIt() -> T? {
		return x
	}
}

This happens when trying to identify the generic depth and index of T in the function getIt. In this case, the type, Swift.Optional<T> gets identified as a generic, but the generic part is embedded and this causes problems.