mozilla/rust — pull request #14299 by kballard (2014-05-19 23:56:27+00:00)
Title: Rename .as_mut() to .as_mut_ref() in Option/Result/AnyMutRefExt

For consistency with other naming patterns, rename .as_mut() to
.as_mut_ref().

Leave .as_mut() as a deprecated function.

[breaking-change]