Unsoundness and accidental features in the <nobr><code>#[target_feature]</code></nobr> attribute

Researching the SemVer hazards of the #[target_feature] attribute led to finding unexpected unsoundness, discovering an "accidental feature" in Rust, finding bugs in rustdoc , the creation of an RFC that evolves the Rust language , and the addition of a dozen new SemVer lints. My work on cargo-semver-checks benefits the Rust ecosystem in more ways than just preventing breakage!