docs: inline std::ffi::c_str types to std::ffi

[notriddle]

Rustdoc has no way to show that an item is stable, but only at a different path. std::ffi::c_str::NulError is not stable, but std::ffi::NulError is.

To avoid marking these types as unstable when someone just wants to follow a link from CString, inline them into their stable paths.

Fixes #134702

r? @tgross35

[notriddle]

Nominating for beta because the risk is low and the docs are very misleading in their current form.

[tgross35]

Thanks for fixing this.

@bors r+ rollup

[bors]

📌 Commit 40b0026 has been approved by tgross35

It is now in the queue for this repository.

[lukas-code]

Shouldn't the re-exports in core and alloc be inlined as well?

[tgross35]

Shouldn't the re-exports in core and alloc be inlined as well?

Good point, may as well get them done at the same time.

@bors r-

[notriddle]

@bors r=tgross35

[bors]

📌 Commit fc8a541 has been approved by tgross35

It is now in the queue for this repository.

[notriddle]

@GuillaumeGomez Should we beta nominate this so that it shows up in the Zulip channel?

[GuillaumeGomez]

Yes please. Go ahead :)

[notriddle]

How do I do that? Adding the label didn't seem to work.

[GuillaumeGomez]

Hum weird, normally just putting the label is supposed to do it...

[GuillaumeGomez]

@Kobzol Did the way to nominate beta backport changed?

[tgross35]

Note that #134851 is also nominated, same change to a different module.

[tgross35]

I just want to double check, @clarfonthey it looks like you marked these no_inline in #112136 - do you remember the reason for this?

[Kobzol]

@Kobzol Did the way to nominate beta backport changed?

I don't think so, but I don't actually know how it worked before 🤷

[clarfonthey]

I just want to double check, @clarfonthey it looks like you marked these no_inline in #112136 - do you remember the reason for this?

Main reason was just that rustdoc always inlines cross-crate exports and I wanted to make it clearer that these are part of the c_str module.