mozilla/rust — pull request #13295 by huonw (2014-04-03 23:26:40+00:00)
Title: rustc: feature-gate `concat_idents!`.

rustc: feature-gate `concat_idents!`.

concat_idents! is not as useful as it could be, due to macros only being
allowed in limited places, and hygiene, so lets feature gate it until we
make a decision about it.

cc #13294