rust-lang/rust — pull request #16891 by eddyb (2014-08-30 22:48:42+00:00)
Title: Allow ExprLit expression macros to be used in patterns.

Enables any macros using `MacExpr` to be treated as patterns when
they produce a literal in the form `ExprLit` (e.g. `stringify!` or `line!`).

Fixes #16876.