auto merge of #8188 : huonw/rust/cfg-macro, r=pcwalton

Example:

    if cfg!(test) {
       calculation_to_run_only_when_testing();
    }

Closes #8130.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/libsyntax/syntax.rs b/src/libsyntax/syntax.rs
index f39351bf91f..4d604faa6e1 100644
--- a/src/libsyntax/syntax.rs
+++ b/src/libsyntax/syntax.rs
@@ -70,6 +70,7 @@ pub mod ext {
     }
 
 
+    pub mod cfg;
     pub mod fmt;
     pub mod env;
     pub mod bytes;