`link_cfg` feature gate is associated to closed issue

[varkor]

rust/src/librustc_feature/active.rs

Lines 334 to 335 in f8b796b

	/// Allows `#[link(..., cfg(..))]`.
	(active, link_cfg, "1.14.0", Some(37406), None),

Relevant issue: #37406.

I'm not sure what the state of this feature is, but we may want to use this issue as a new tracking issue.

[Elinvynia]

The linked issue mentions that this feature will never be stable, so I think there isn't a need in tracking it. I see that there is some effort in documenting this behavior here: #71586