Update src/borrow_check/region_inference.md
Update src/borrow_check/region_inference.md

Co-Authored-By: csmoe <33e0fe6db386e512e99222184073d6fd8c1e4db7@msn.com>
rust-lang/rustc-dev-guide,rust-lang/rustc-dev-guide,rust-lang/rustc-dev-guide,rust-lang/rustc-dev-guide