Explaining how to link mixed C/Rust binaries.

[adetaylor]

Discussed in rust-lang/rust#73632

[ehuss]

Thanks for the PR! In general, we want the reference to be more about the language, and less about the implementation. To that end, I think this content is better suited for the rustc book. In a sense, almost the entirety of this chapter should probably move, but I am uncertain how exactly that should be structured. So I'm a bit reluctant to continue down the path of adding more compiler-specific information. Maybe you would be interested in figuring out how to untangle this and figure out how to organize things?

[adetaylor]

Hi @ehuss, thanks for the comment. I understand this chapter is in a slightly odd status. I'm afraid I'm not likely to be the Untangler here, sorry! Shall I abandon this PR or can I convince you that it doesn't really make things worse?

[traviscross]

In talking through this on the lang-docs call, we're going to go ahead and merge this so that it lands with wherever the rest of this chapter lands, when we get around to cleaning all this up.