Make most of std::rt private

Previously, the entire runtime API surface was publicly exposed, but
that is neither necessary nor desirable. This commit hides most of the
module, using librustrt directly as needed. The arrangement will need to
be revisited when rustrt is pulled into std.

[breaking-change]

1 files changed, 1 insertions, 1 deletions

diff --git a/src/libstd/sys/unix/pipe.rs b/src/libstd/sys/unix/pipe.rs
index 3fba06e0c7f..4d3469a9c24 100644
--- a/src/libstd/sys/unix/pipe.rs
+++ b/src/libstd/sys/unix/pipe.rs
@@ -12,7 +12,7 @@ use alloc::arc::Arc;
 use libc;
 use c_str::CString;
 use mem;
-use rt::mutex;
+use rustrt::mutex;
 use sync::atomic;
 use io::{mod, IoResult, IoError};
 use prelude::*;