Remove rt::bookkeeping

This commit removes the runtime bookkeeping previously used to ensure
that all Rust tasks were joined before the runtime was shut down.

This functionality will be replaced by an RAII style `Thread` API, that
will also offer a detached mode.

Since this changes the semantics of shutdown, it is a:

[breaking-change]

1 files changed, 1 insertions, 2 deletions

diff --git a/src/libstd/sys/common/helper_thread.rs b/src/libstd/sys/common/helper_thread.rs
index ffb053e852e..ef0181b72b0 100644
--- a/src/libstd/sys/common/helper_thread.rs
+++ b/src/libstd/sys/common/helper_thread.rs
@@ -25,7 +25,7 @@ use prelude::*;
 use cell::UnsafeCell;
 use mem;
 use sync::{StaticMutex, StaticCondvar};
-use rt::{mod, bookkeeping};
+use rt;
 use sys::helper_signal;
 
 use task;
@@ -83,7 +83,6 @@ impl<M: Send> Helper<M> {
 
                 let t = f();
                 task::spawn(move |:| {
-                    bookkeeping::decrement();
                     helper(receive, rx, t);
                     let _g = self.lock.lock();
                     *self.shutdown.get() = true;