6379c727ac
rustdoc: Add PartialOrd trait to doc comment explanation The doc comments for [partial_cmp](https://github.com/rust-lang/rust/blob/master/library/core/src/iter/traits/iterator.rs#L3478) is the exact same as the doc comment for [cmp](https://github.com/rust-lang/rust/blob/master/library/core/src/iter/traits/iterator.rs#L3413). This PR adds to the description `partial_cmp` to disambiguate the description from `cmp.`