Fixes for new rust nightlies

[jrasky]

Fixes for recent changes in Rust.

All tests pass, and this time I'm fairly certain the changes haven't already been committed.

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @huonw (or someone else) soon.

If any changes to this PR are deemed necessary, please add them as extra commits. This ensures that the reviewer can see what has changed since they last reviewed the code. The way Github handles out-of-date commits, this should also make it reasonably obvious what issues have or haven't been addressed. Large or tricky changes may require several passes of review and changes.

Please see CONTRIBUTING.md for more information.

[alexcrichton]

Thanks! Currently this repo builds with the most recent nightly, not the current master branch of Rust (although normally the two are pretty close together).

We'll be sure to merge this quickly once nightly updates!

[BurntSushi]

Thank you! :-)

[BurntSushi]

OK, this fix is in 0.1.13 on crates.io (but can't update regex_macros yet).

@alexcrichton Could you add me as an owner to the regex_macros crate? :-)

[alexcrichton]

Done!