Rollup of 9 pull requests

[Centril]

Successful merges:

• Add lint when no doc is present at the crate-level #66938 (Add lint when no doc is present at the crate-level)
• Replace some desc logic in librustc_lint with article_and_desc #69740 (Replace some desc logic in librustc_lint with article_and_desc)
• Evaluate repeat expression lengths as late as possible #69981 (Evaluate repeat expression lengths as late as possible)
• Make needs_drop less pessimistic on generators #70015 (Make needs_drop less pessimistic on generators)
• Fix invalid suggestion on &mut iterators yielding & references #70264 (Fix invalid suggestion on &mut iterators yielding & references)
• get rid of ConstPropUnsupported; use ZST marker structs instead #70267 (get rid of ConstPropUnsupported; use ZST marker structs instead)
• Remove ReClosureBound #70277 (Remove ReClosureBound)
• Account for bad placeholder types in where clauses #70294 (Account for bad placeholder types in where clauses)
• Clean up E0452 explanation #70309 (Clean up E0452 explanation)

Failed merges:

r? @ghost

[Centril]

@bors r+ p=9 rollup=never

[bors]

📌 Commit c98c56e has been approved by Centril

[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.

2020-03-23T22:17:03.0522807Z ========================== Starting Command Output ===========================
2020-03-23T22:17:03.0540866Z [command]/bin/bash --noprofile --norc /home/vsts/work/_temp/ec74ffb1-6882-4029-b3b3-09f7ddbb4498.sh
2020-03-23T22:17:03.0731661Z 
2020-03-23T22:17:03.0787200Z ##[section]Finishing: Disable git automatic line ending conversion
2020-03-23T22:17:03.0811327Z ##[section]Starting: Checkout rust-lang/rust@refs/pull/70335/merge to s
2020-03-23T22:17:03.0814897Z Task         : Get sources
2020-03-23T22:17:03.0815211Z Description  : Get sources from a repository. Supports Git, TfsVC, and SVN repositories.
2020-03-23T22:17:03.0815871Z Version      : 1.0.0
2020-03-23T22:17:03.0816379Z Author       : Microsoft
---
2020-03-23T22:17:03.8443458Z ##[command]git remote add origin https://github.com/rust-lang/rust
2020-03-23T22:17:03.8448852Z ##[command]git config gc.auto 0
2020-03-23T22:17:03.8452465Z ##[command]git config --get-all http.https://github.com/rust-lang/rust.extraheader
2020-03-23T22:17:03.8455828Z ##[command]git config --get-all http.proxy
2020-03-23T22:17:03.8462501Z ##[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/70335/merge:refs/remotes/pull/70335/merge
---
2020-03-23T22:25:13.6199513Z configure: build.locked-deps    := True
2020-03-23T22:25:13.6199819Z configure: llvm.ccache          := sccache
2020-03-23T22:25:13.6200323Z configure: build.cargo-native-static := True
2020-03-23T22:25:13.6200802Z configure: dist.missing-tools   := True
2020-03-23T22:25:13.6201380Z configure: build.configure-args := ['--enable-sccache', '--disable-manage-submodu ...
2020-03-23T22:25:13.6201967Z configure: writing `config.toml` in current directory
2020-03-23T22:25:13.6202202Z configure: 
2020-03-23T22:25:13.6202596Z configure: run `python /checkout/x.py --help`
2020-03-23T22:25:13.6202842Z configure: 
---
2020-03-23T22:32:37.8978988Z skip untracked path src/doc/rust-by-example/ during rustfmt invocations
2020-03-23T22:32:37.8979788Z skip untracked path src/llvm-project/ during rustfmt invocations
2020-03-23T22:32:41.1148539Z Diff in /checkout/src/librustc/ty/sty.rs at line 2274:
2020-03-23T22:32:41.1148821Z  
2020-03-23T22:32:41.1149067Z          let body_id = match tcx.hir().get(hir_id) {
2020-03-23T22:32:41.1149404Z              hir::Node::AnonConst(ac) => ac.body,
2020-03-23T22:32:41.1150809Z -            _ => span_bug!(tcx.def_span(def_id.to_def_id()), "from_anon_const can only process anonymous constants"),
2020-03-23T22:32:41.1151208Z +            _ => span_bug!(
2020-03-23T22:32:41.1151468Z +                tcx.def_span(def_id.to_def_id()),
2020-03-23T22:32:41.1151816Z +                "from_anon_const can only process anonymous constants"
2020-03-23T22:32:41.1152254Z          };
2020-03-23T22:32:41.1152390Z  
2020-03-23T22:32:41.1152618Z          let expr = &tcx.hir().body(body_id).value;
2020-03-23T22:32:41.1152618Z          let expr = &tcx.hir().body(body_id).value;
2020-03-23T22:32:41.1172869Z Running `"/checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/rustfmt" "--config-path" "/checkout" "--edition" "2018" "--unstable-features" "--skip-children" "--check" "/checkout/src/librustc/ty/sty.rs"` failed.
2020-03-23T22:32:41.1173934Z If you're running `tidy`, try again with `--bless` flag. Or, you just want to format code, run `./x.py fmt` instead.
2020-03-23T22:32:41.1189769Z Build completed unsuccessfully in 0:00:39
2020-03-23T22:32:41.1237289Z == clock drift check ==
2020-03-23T22:32:41.1249322Z   local time: Mon Mar 23 22:32:41 UTC 2020
2020-03-23T22:32:41.3871624Z   network time: Mon, 23 Mar 2020 22:32:41 GMT
2020-03-23T22:32:41.3871624Z   network time: Mon, 23 Mar 2020 22:32:41 GMT
2020-03-23T22:32:41.3872796Z == end clock drift check ==
2020-03-23T22:32:42.8101405Z 
2020-03-23T22:32:42.8168995Z ##[error]Bash exited with code '1'.
2020-03-23T22:32:42.8188701Z ##[section]Finishing: Run build
2020-03-23T22:32:42.8237641Z ##[section]Starting: Checkout rust-lang/rust@refs/pull/70335/merge to s
2020-03-23T22:32:42.8242577Z Task         : Get sources
2020-03-23T22:32:42.8242922Z Description  : Get sources from a repository. Supports Git, TfsVC, and SVN repositories.
2020-03-23T22:32:42.8243234Z Version      : 1.0.0
2020-03-23T22:32:42.8243475Z Author       : Microsoft
2020-03-23T22:32:42.8243475Z Author       : Microsoft
2020-03-23T22:32:42.8243824Z Help         : [More Information](https://go.microsoft.com/fwlink/?LinkId=798199)
2020-03-23T22:32:42.8244230Z ==============================================================================
2020-03-23T22:32:43.1537730Z Cleaning any cached credential from repository: rust-lang/rust (GitHub)
2020-03-23T22:32:43.1588948Z ##[section]Finishing: Checkout rust-lang/rust@refs/pull/70335/merge to s
2020-03-23T22:32:43.1679076Z Cleaning up task key
2020-03-23T22:32:43.1680549Z Start cleaning up orphan processes.
2020-03-23T22:32:43.1864812Z Terminate orphan process: pid (4078) (python)
2020-03-23T22:32:43.2084269Z ##[section]Finishing: Finalize Job

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