fix: don't force a newline after an empty where clause (master)

[meiomorphism]

Rebase of #4548 onto master. Clean.

[meiomorphism]

I've looked at several of the CI failures; they all seem to be from rustc-ap-rustc_data_structures-686.0.0, due to the recent rename of the optin_builtin_traits feature to auto_traits (rust-lang/rust@810324d).

Presumably updating to 690.0.0 will fix that.

[calebcartwright]

Don't worry about the broken CI for now, it's a broken toolstate issue - rust-lang/rust#79407

[calebcartwright]

When you get a chance could you rebase on master? CI checks should be good now

[meiomorphism]

Pinging, since I've forgotten whether GitHub pings on branch updates, and now suspect that it doesn't.

[calebcartwright]

Pinging, since I've forgotten whether GitHub pings on branch updates, and now suspect that it doesn't.

Thanks. I believe it does, at least for non-rebases, but also entirely possible that I missed this one amongst the notification noise

[karyon]

backported in #4548