FR: Runtime linking support for multiple platforms

### Edit

This has been issue has been turned into a feature request. The rules should support runtime linking on multiple platforms (more than just linux).

### Original

Can anyone explain why this is the case?
https://github.com/bazelbuild/rules_rust/blob/22d67305d80fbc1f0f3e959b3d520e908cf7f9aa/rust/private/rustc.bzl#L758-L762

Looking back at https://github.com/bazelbuild/rules_rust/pull/121 and then https://github.com/bazelbuild/rules_rust/pull/61 there doesn't seem to be anything calling out that this is specific to linux other than the fact that the PR was only scoped to linux.

Is this still correct that only this behavior is only possible on linux? If so, why is linux the only platform that can do this? If not, what would be the risk in expanding this to other platforms?

(hoping @mfarrugi might know since they appear to have been the original author)