Auto merge of #80322 - ehuss:update-cargo, r=ehuss

Auto merge of #80322 - ehuss:update-cargo, r=ehuss

Update cargo

10 commits in a3c2627fbc2f5391c65ba45ab53b81bf71fa323c..75d5d8cffe3464631f82dcd3c470b78dc1dda8bb
2020-12-14 17:21:26 +0000 to 2020-12-22 18:10:56 +0000
- Update git2 (rust-lang/cargo#9009)
- Stabilize RUSTC_WORKSPACE_WRAPPER (rust-lang/cargo#8976)
- Make cargo metadata and tree respect target (rust-lang/cargo#8987)
- Update git2 (rust-lang/cargo#8998)
- Revert rust-lang/cargo#8954 - changing rustdoc's cwd (rust-lang/cargo#8996)
- With debug HTTP mode log curl's version (rust-lang/cargo#8991)
- Reject ambiguous git dependency declaration. (rust-lang/cargo#8984)
- Fix tests not working with a different CARGO_TARGET_DIR. (rust-lang/cargo#8982)
- Add version to credential dependencies. (rust-lang/cargo#8983)
- Clarify FAQ entry wording about lockfiles (rust-lang/cargo#8978)