Rollup of 5 pull requests

[RalfJung]

Successful merges:

• Rework MIR drop tree lowering #71840 (Rework MIR drop tree lowering)
• Update the cc crate #71882 (Update the cc crate)
• Update transitive dependency to work towards removing syn <1.0 dep #71919 (Update transitive dependency to work towards removing syn <1.0 dep)
• Sort "implementations on foreign types" section in the sidebar #71945 (Sort "implementations on foreign types" section in the sidebar)
• Add missing backtick in E0569 explanation #72043 (Add missing backtick in E0569 explanation)

Failed merges:

r? @ghost

[RalfJung]

@bors r+ rollup=never p=5

[bors]

📌 Commit 0a646ef has been approved by RalfJung

[RalfJung]

@rustbot modify labels: +rollup

[RalfJung]

That's a weird GHA failure:

error: failed to write /checkout/Cargo.lock

Caused by:
  failed to open: /checkout/Cargo.lock

Caused by:
  Read-only file system (os error 30)

Cc @rust-lang/infra

EDIT: Oh, same on Azure...?

[rust-highfive]

The job mingw-check of your PR failed (pretty log, raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

##[section]Starting: Linux mingw-check
##[section]Starting: Initialize job
Agent name: 'Azure Pipelines 64'
Agent machine name: 'fv-az578'
Current agent version: '2.168.2'
##[group]Operating System
16.04.6
LTS
LTS
##[endgroup]
##[group]Virtual Environment
Environment: ubuntu-16.04
Version: 20200430.2
Included Software: https://github.com/actions/virtual-environments/blob/ubuntu16/20200430.2/images/linux/Ubuntu1604-README.md
##[endgroup]
Agent running as: 'vsts'
Prepare build directory.
Set build variables.
Download all required tasks.
Download all required tasks.
Downloading task: Bash (3.163.1)
Checking job knob settings.
   Knob: AgentToolsDirectory = /opt/hostedtoolcache Source: ${AGENT_TOOLSDIRECTORY} 
   Knob: AgentPerflog = /home/vsts/perflog Source: ${VSTS_AGENT_PERFLOG} 
Start tracking orphan processes.
##[section]Finishing: Initialize job
##[section]Starting: Configure Job Name
==============================================================================
---
========================== Starting Command Output ===========================
[command]/bin/bash --noprofile --norc /home/vsts/work/_temp/b27c450e-b77e-4f69-b89b-882d81a0630c.sh

##[section]Finishing: Disable git automatic line ending conversion
##[section]Starting: Checkout rust-lang/rust@refs/pull/72073/merge to s
Task         : Get sources
Description  : Get sources from a repository. Supports Git, TfsVC, and SVN repositories.
Version      : 1.0.0
Author       : Microsoft
---
##[command]git remote add origin https://github.com/rust-lang/rust
##[command]git config gc.auto 0
##[command]git config --get-all http.https://github.com/rust-lang/rust.extraheader
##[command]git config --get-all http.proxy
##[command]git -c http.extraheader="AUTHORIZATION: basic ***" fetch --force --tags --prune --progress --no-recurse-submodules --depth=2 origin +refs/heads/*:refs/remotes/origin/* +refs/pull/72073/merge:refs/remotes/pull/72073/merge
---
 ---> 3adb0605cc65
Step 6/7 : ENV RUN_CHECK_WITH_PARALLEL_QUERIES 1
 ---> Using cache
 ---> 28dbc326cb7f
Step 7/7 : ENV SCRIPT python3 ../x.py test src/tools/expand-yaml-anchors &&            python3 ../x.py check --target=i686-pc-windows-gnu --host=i686-pc-windows-gnu &&            python3 ../x.py build --stage 0 src/tools/build-manifest &&            python3 ../x.py test --stage 0 src/tools/compiletest &&            python3 ../x.py test src/tools/tidy &&            python3 ../x.py doc --stage 0 src/libstd &&            /scripts/validate-toolstate.sh
 ---> 537a01811900
Successfully built 537a01811900
Successfully tagged rust-ci:latest
Built container sha256:537a018119009dc218456238dec90b5530050db1e2a1e166550c218003f6159d
---
  local time: Sun May 10 09:31:28 UTC 2020
  network time: Sun, 10 May 2020 09:31:28 GMT
== end clock drift check ==

##[error]Bash exited with code '1'.
##[section]Finishing: Run build
##[section]Starting: Checkout rust-lang/rust@refs/pull/72073/merge to s
Task         : Get sources
Description  : Get sources from a repository. Supports Git, TfsVC, and SVN repositories.
Version      : 1.0.0
Author       : Microsoft
Author       : Microsoft
Help         : [More Information](https://go.microsoft.com/fwlink/?LinkId=798199)
==============================================================================
Cleaning any cached credential from repository: rust-lang/rust (GitHub)
##[section]Finishing: Checkout rust-lang/rust@refs/pull/72073/merge to s
Cleaning up task key
Start cleaning up orphan processes.
Terminate orphan process: pid (3920) (python)
##[section]Finishing: Finalize Job

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @rust-lang/infra. (Feature Requests)

[RalfJung]

Maybe that's a weird way to tell me the lockfile is outdated? I'll recreate with fewer PRs. (EDIT: that's #72074)

[RalfJung]

@bors r-

[RalfJung]

It used to be the case that when the lockfile is outdated the cargo error clearly said that: something about "working with --locked but lockfile needs updating, aborting" or so. Since then the error message regressed to make this look like a mistake in how the file system is set up.