Rollup of 10 pull requests

[Centril]

Successful merges:

• Stabilize todo macro #61879 (Stabilize todo macro)
• Deprecate #![plugin] & #[plugin_registrar] #64675 (Deprecate #![plugin] & #[plugin_registrar])
• add regression test for #60218 #64706 (add regression test for ICE on higher-trait bounds #60218)
• Prevent rustdoc feature doctests #64741 (Prevent rustdoc feature doctests)
• Replace mentions of IRC with Discord #65004 (Replace mentions of IRC with Discord)
• Always mark rust and rust-call abi's as unwind #65020 (Always mark rust and rust-call abi's as unwind)
• metadata: Some crate loading cleanup #65026 (metadata: Some crate loading cleanup)
• Add long error explanation for E0556 #65055 (Add long error explanation for E0556)
• Make visit projection iterative #65056 (Make visit projection iterative)
• typo: fix typo in E0392 #65057 (typo: fix typo in E0392)

Failed merges:

r? @ghost

[Centril]

@bors r+ p=10 rollup=never

[bors]

📌 Commit dd97e17 has been approved by Centril

[bors]

⌛ Testing commit dd97e17 with merge 53574d6406f33fa152e43caf2730ca496df6d46a...

[bors]

💔 Test failed - checks-azure

[rust-highfive]

The job dist-powerpc64-linux 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.

2019-10-03T20:59:16.7292508Z    Compiling arena v0.0.0 (/checkout/src/libarena)
2019-10-03T20:59:17.1747966Z [RUSTC-TIMING] arena test:false 0.440
2019-10-03T20:59:17.1792999Z    Compiling syntax_pos v0.0.0 (/checkout/src/libsyntax_pos)
2019-10-03T20:59:17.2366833Z [RUSTC-TIMING] tempfile test:false 3.615
2019-10-03T20:59:17.2399764Z error: /checkout/obj/build/x86_64-unknown-linux-gnu/stage1-rustc/release/deps/librustc_macros-f9c41f60c3e440f1.so: undefined symbol: __rustc_proc_macro_decls_7b3f997c3f27a6e9835a42bc866723ac__
2019-10-03T20:59:17.2400170Z  --> src/libsyntax_pos/symbol.rs:8:5
2019-10-03T20:59:17.2400682Z 8 | use rustc_macros::symbols;
2019-10-03T20:59:17.2401305Z   |     ^^^^^^^^^^^^
2019-10-03T20:59:17.2401359Z 
2019-10-03T20:59:17.2417103Z error: aborting due to previous error
---
2019-10-03T20:59:17.2617578Z == clock drift check ==
2019-10-03T20:59:17.2630921Z   local time: Thu Oct  3 20:59:17 UTC 2019
2019-10-03T20:59:17.4106937Z   network time: Thu, 03 Oct 2019 20:59:17 GMT
2019-10-03T20:59:17.4114088Z == end clock drift check ==
2019-10-03T20:59:19.0974127Z ##[error]Bash exited with code '1'.
2019-10-03T20:59:19.1018285Z ##[section]Starting: Upload CPU usage statistics
2019-10-03T20:59:19.1025990Z ==============================================================================
2019-10-03T20:59:19.1026123Z Task         : Bash
2019-10-03T20:59:19.1026221Z Description  : Run a Bash script on macOS, Linux, or Windows

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 @TimNN. (Feature Requests)