Don't squash path dependencies with same package name

[ldm0]

Fixes #13862

Dependencies with same package name in the Cargo.lock was squashed in EncodableResolve::into_resolve().

e.g. In the problem reproduction repo's Cargo.lock, there are two entries:

[[package]]
name = "once_cell"
version = "0.1.0"

[[package]]
name = "once_cell"
version = "1.19.0"

However, they were squashed in build_path_deps(), then we endup getting two package ids with same path like this:

PackageId { name: "once_cell", version: "0.1.0", source: "pwd/vendor/once_cell_1_19" }
PackageId { name: "once_cell", version: "1.19.0", source: "pwd/vendor/once_cell_1_19" }

This package version inconsistency triggers patch update introduced in #8248 everytime you compile this crate.

[rustbot]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @weihanglo (or someone else) some time within the next two weeks.

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[ldm0]

Use last() for behaviour consistency with old cargo. Old cargo use HashMap and insert for path deps construction, therefore the last inserted package was picked.

[epage]

Note: I just did a quick scan of the issue (and commit structure). I've not looked at the test or code change in detail yet

[ldm0]

It seems that CI failure is caused by check-cfg https://github.com/rust-lang/cargo/actions/runs/8964218728/job/24615675343?pr=13863
Related: #13571

[ldm0]

ping @weihanglo

[bors]

☔ The latest upstream changes (presumably #13931) made this pull request unmergeable. Please resolve the merge conflicts.

[weihanglo]

Sorry for the late reply. Thought epage was on it. Feel free to open a new one whenever ready.