Auto merge of #69627 - ehuss:update-cargo-clippy, r=Dylan-DPC

Auto merge of #69627 - ehuss:update-cargo-clippy, r=Dylan-DPC

Update cargo, clippy

Closes #69601

## cargo

16 commits in e57bd02999c9f40d52116e0beca7d1dccb0643de..bda50510d1daf6e9c53ad6ccf603da6e0fa8103f
2020-02-21 20:20:10 +0000 to 2020-03-02 18:05:34 +0000
- Fix rare failure in collision_export test. (rust-lang/cargo#7956)
- Ignore broken Cargo.toml in git sources (rust-lang/cargo#7947)
- Add more fingerprint mtime debug logging. (rust-lang/cargo#7952)
- Fix plugin tests for latest nightly. (rust-lang/cargo#7955)
- Simplified usage code of SipHasher (rust-lang/cargo#7945)
- Add a special case for git config discovery inside tests (rust-lang/cargo#7944)
- Fixes issue rust-lang/cargo#7543 (rust-lang/cargo#7946)
- Filter out cfgs which should not be used during build (rust-lang/cargo#7943)
- Provide extra context on a query failure. (rust-lang/cargo#7934)
- Try to clarify `cargo metadata`'s relationship with the workspace. (rust-lang/cargo#7927)
- Update libgit2 dependency (rust-lang/cargo#7939)
- Fix link in comment (rust-lang/cargo#7936)
- Enable `cargo doc --open` tests on macos. (rust-lang/cargo#7932)
- build-std: remove sysroot probe (rust-lang/cargo#7931)
- Try to clarify how feature flags work on the "current" package. (rust-lang/cargo#7928)
- Add extra details in the new feature resolver doc comment. (rust-lang/cargo#7918)

## clippy

6 commits in fc5d0cc583cb1cd35d58fdb7f3e0cfa12dccd6c0..8b7f7e667268921c278af94ae30a61e87a22b22b
2020-02-24 05:58:17 +0000 to 2020-03-02 20:00:31 +0000
- Rustup to rust-lang/rust#69469 (rust-lang-nursery/rust-clippy#5254)
- Some rustups (rust-lang-nursery/rust-clippy#5247)
- Update git2 to 0.12 (rust-lang-nursery/rust-clippy#5232)
- Rustup to rust-lang/rust#61812 (rust-lang-nursery/rust-clippy#5231)
- Add lint to improve floating-point expressions (rust-lang-nursery/rust-clippy#4897)
- Do not run deploy action on other repos (rust-lang-nursery/rust-clippy#5222)