update racer/rustfmt to complete rustc-ap* bump

[calebcartwright]

Update racer and rustfmt to fix broken toolstates

Refs:

• rls no longer builds after rust-lang/rust#73190 rust#73199
• rustfmt no longer builds after rust-lang/rust#73190 rust#73200
• bump rustfmt 1.x rustc-ap* crates to v644 rustfmt#4253
• bump rustc-ap-* crates to v664 racer-rust/racer#1115

[calebcartwright]

@topecongiro - this means that we would technically have a breaking API change in rustfmt 1.4.18 on to_toml() (the error value is now ToTomlError instead of String) due to the backporting of rust-lang/rustfmt#3948. I actually forgot that this was public in the rustfmt lib and consumed by rls.

I've opened this as-is in case you and @Xanewok want to accept this change and proceed in order to fix the broken toolstates. Otherwise we'd probably want to yank v.14.18 of rustfmt, and then either publish v1.4.19 that still has the parser bug users keep reporting, or try to reimplement a fix using the now-deprecated failure

[calebcartwright]

Also had to tweak the CI config a bit to include the llvm-tools-preview component and ensure that CFG_RELEASE and CFG_RELEASE_CHANNEL were flowing through (they're defined is vars in the job config but I was still getting errors like the one shown below without setting them inline in the test jobs)

https://dev.azure.com/rust-lang/rls/_build/results?buildId=32077&view=logs&j=7fcbd5f9-4927-5bd9-bd50-f9f24db86f8d&t=30fe560a-7e17-5e89-0250-d3688963a3cf

error: environment variable `CFG_RELEASE_CHANNEL` not defined
   --> /home/vsts/.cargo/registry/src/git.luolix.top-1ecc6299db9ec823/rustc-ap-rustc_attr-664.0.0/builtin.rs:655:27
    |
655 |             let channel = env!("CFG_RELEASE_CHANNEL");
    |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

error: environment variable `CFG_RELEASE` not defined
   --> /home/vsts/.cargo/registry/src/git.luolix.top-1ecc6299db9ec823/rustc-ap-rustc_attr-664.0.0/builtin.rs:657:48
    |
657 |             let rustc_version = Version::parse(env!("CFG_RELEASE")).unwrap();
    |                                                ^^^^^^^^^^^^^^^^^^^
    |
    = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

error: aborting due to 2 previous errors

error: could not compile `rustc-ap-rustc_attr`.

[Xanewok]

I don't think RLS will build on stable/beta in the nearest future so I think we should just globally set these variables for simplicity and call it a day

[bors]

☔ The latest upstream changes (presumably fb46b91) made this pull request unmergeable. Please resolve the merge conflicts.

[Xanewok]

@calebcartwright sorry for the delay. I hope you don't mind that I merged the previous branch I had prepared (https://github.com/rust-lang/rls/tree/rustc-ap-664) so that we don't need to change back the envs in the CI config.

From what I've seen there was yet another failure on master wrt Extend changes and I believe we still need to do the rustc-ap-* upgrade dance...

Since the relevant changes has been merged already, I'll close this now.

[calebcartwright]

@calebcartwright sorry for the delay.

No worries @Xanewok ! I probably should've checked with you or perused the branches more thoroughly first to make sure you weren't working on it already 😄

From what I've seen there was yet another failure on master wrt Extend changes and I believe we still need to do the rustc-ap-* upgrade dance...

I'm not sure I follow 🤔 racer v2.1.35 and rustfmt 1.4.18 (looks like on rls master rustfmt is still 1.4.16) have already been updated and should be good to go. Or are you saying there's additional breaking upstream rustc changes and we need to start the dance all over?

[Xanewok]

(...) Or are you saying there's additional breaking upstream rustc changes (...)

So I've tried to test the update on master Rust with this patch applied and bumps to RLS/Rustfmt and I found that there was some additional breakage which led me to postpone the update in the first place... but I did try it again just now and it seemed to work? Not sure if I did something wrong the first time around or is there something that I didn't do correctly now 🤷

In any case, I've submitted rust-lang/rust#73506; let's see if the tools job is happy and if so we can r+ and hopefully finally unbreak the toolstate.

[calebcartwright]

Gotcha, thank you! And now we wait 🤞