librustc: Stop reexporting the standard modules from prelude.
diff --git a/src/test/run-pass/const-fields-and-indexing.rs b/src/test/run-pass/const-fields-and-indexing.rs
index ccc7b48..990e5e6 100644
--- a/src/test/run-pass/const-fields-and-indexing.rs
+++ b/src/test/run-pass/const-fields-and-indexing.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+use std::io;
+
 static x : [int, ..4] = [1,2,3,4];
 static p : int = x[2];
 static y : &'static [int] = &[1,2,3,4];