Box validity: update for new zero-sized rules Fixes https://github.com/rust-lang/unsafe-code-guidelines/issues/529 Cc `@joshlf` `@rust-lang/opsem`
Box validity: update for new zero-sized rules Fixes https://github.com/rust-lang/unsafe-code-guidelines/issues/529 Cc `@joshlf` `@rust-lang/opsem`