Fix IpAddr link when IpAddr moves to core

[faern]

Small change needed in order to make CI pass over at rust-lang/rust#104265

[faern]

The CI breaks this PR because I make the link broken. But the CI in the other PR also breaks because I make the link broken. It's a catch 22. We need to break it here first so that the other PR can be merged in order to fix it again?

[carols10cents]

I note that your PR says:

Implements the (not yet approved) RFC rust-lang/rfcs#2832.

I don't want to merge this until the RFC gets approved. I can look into what it would take to ignore that link, or less ideally ignore CI here, when that's the case.

But actually, isn't this change going to break any links that are out there to https://doc.rust-lang.org/stable/std/net/enum.IpAddr.html ? Shouldn't we figure out how to do a redirect to avoid breaking those links?

[faern]

I note that your PR says:

Implements the (not yet approved) RFC rust-lang/rfcs#2832.

The FCP has completed with the disposition to merge. So I dunno, I think it's currently just waiting for this PR to be ready to merge. I wrote that PR description before the FCP completed.

[pitaj]

Is this PR still needed? Looks like rust-lang/rust#104265 no longer uses a type alias for this.

[faern]

No longer needed if the other PR is accepted as is. I have not yet heard any feedback on this not-type-aliasing-solution so I have not closed this yet