Fix typos and punctuation
Fix typos and punctuation

Co-Authored-By: scalexm <b30f4169e054ee7b8c243480bcfcef62416f3b08@scalexm.fr>

rust-lang/rustc-dev-guide,rust-lang/rustc-dev-guide,rust-lang/rustc-dev-guide,rust-lang/rustc-dev-guide