feat: Visualize compiler inserted reborrows via inlay hints

[Veykril]

Disabled by default.

Closes #11275

[Veykril]

bors r+

[bors]

Build succeeded:

• Rust (macos-latest)
• Rust (ubuntu-latest)
• Rust (windows-latest)
• TypeScript (ubuntu-latest)
• TypeScript (windows-latest)

[flodiebold]

It would be nice to be able to toggle visualizations like this and the implicit lifetimes, I guess. Probably very few people will want to turn them on permanently, but would sometimes want to see them.

[Veykril]

Ye hence why I've disabled them by default. Iirc you can (at least in VSCode) bind configuration toggles to buttons? I'll check that, would probably be good to mention that in the changelog if that is indeed possible.

[Veykril]

Ah nvm, we added an extra thing for that #4601

[Veykril]

So, I personally don't feel too good about adding a toggle X command for all these things that we might have and as it turns out (at least for VSCode) you can do arbitrary config toggles by adding an extension and then adding to your keybindings like written here https://medium.com/hack-visual-studio-code/toggle-any-setting-in-vs-code-using-keyboard-shortcut-arguments-cdb5ddc56955
Which sounds like the better overall solution to me to point people to.

[lnicola]

Can we drop #4601 then? 😆

[Veykril]

I'd say yes :)

[flodiebold]

I wouldn't want to add a toggle command for all the things. I do think though that if we want to provide a good user experience for this, we should provide some way of showing it temporarily and not require a hack with another extension. (Is it even possible to toggle the setting without restarting the server?)

[Veykril]

Yes changing inlay hint settings retriggers them.