thir::pattern: update some comments and error type names Follow-up to [these comments](https://github.com/rust-lang/rust/pull/105750#pullrequestreview-1629697578). Please carefully fact-check, I'm new to this area of the compiler!
thir::pattern: update some comments and error type names Follow-up to [these comments](https://github.com/rust-lang/rust/pull/105750#pullrequestreview-1629697578). Please carefully fact-check, I'm new to this area of the compiler!