Rollup merge of rust-lang#83070 - ehuss:update-cargo, r=ehuss

Update cargo

7 commits in 970bc67c3775781b9708c8a36893576b9459c64a..32da9eaa5de5be241cf8096ca6b749a157194f77
2021-03-07 18:09:40 +0000 to 2021-03-13 01:18:40 +0000
- Fix logic for determining prefer-dynamic for a dylib. (rust-lang/cargo#9252)
- Fix issue with filtering exclusive target dependencies. (rust-lang/cargo#9255)
- Update pkgid-spec docs. (rust-lang/cargo#9249)
- Wordsmith the edition documentation a bit more (rust-lang/cargo#9233)
- Package ID specification urls must contain a host (rust-lang/cargo#9188)
- Add documentation for JSON message_path. (rust-lang/cargo#9247)
- Fix filter_platform to run on targets other than x86. (rust-lang/cargo#9246)