rust-lang/rust — pull request #14988 by pcwalton (2014-06-17 23:02:09+00:00)
Title: librustc: Put `#[unsafe_destructor]` behind a feature gate.

Closes #8142.

This is not the semantics we want long-term. You can continue to use
`#[unsafe_destructor]`, but you'll need to add
`#![feature(unsafe_destructor)]` to the crate attributes.

[breaking-change]

r? @alexcrichton