Status of :win32 perlio layer?

I was wondering about the status of the :win32 perlio layer. It's been
marked as experimental for ages.

What is preventing it from becoming non-experimental? What is not
working/missing?

(CC-ing bulk because he's the last person who worked on it)

• Status of :win32 perlio layer? by Tomasz Konojacki
• Re: Status of :win32 perlio layer? by bulk88