std: Internalize almost all of `std::rt`

This commit does some refactoring to make almost all of the `std::rt` private.
Specifically, the following items are no longer part of its API:

* DEFAULT_ERROR_CODE
* backtrace
* unwind
* args
* at_exit
* cleanup
* heap (this is just alloc::heap)
* min_stack
* util

The module is now tagged as `#[doc(hidden)]` as the only purpose it's serve is
an entry point for the `panic!` macro via the `begin_unwind` and
`begin_unwind_fmt` reexports.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/libstd/io/lazy.rs b/src/libstd/io/lazy.rs
index 5424fec8110..65667f24dda 100644
--- a/src/libstd/io/lazy.rs
+++ b/src/libstd/io/lazy.rs
@@ -12,8 +12,8 @@ use prelude::v1::*;
 
 use cell::Cell;
 use ptr;
-use rt;
 use sync::{StaticMutex, Arc};
+use sys_common;
 
 pub struct Lazy<T> {
     lock: StaticMutex,
@@ -51,7 +51,7 @@ impl<T: Send + Sync + 'static> Lazy<T> {
         // `Arc` allocation in our own internal box (it will get deallocated by
         // the at exit handler). Otherwise we just return the freshly allocated
         // `Arc`.
-        let registered = rt::at_exit(move || {
+        let registered = sys_common::at_exit(move || {
             let g = self.lock.lock();
             let ptr = self.ptr.get();
             self.ptr.set(1 as *mut _);