rustc: Update how Gc<T> is recognized

This commit uses the same trick as ~/Box to map Gc<T> to @T internally inside
the compiler. This moves a number of implementations of traits to the `gc`
module in the standard library.

This removes functions such as `Gc::new`, `Gc::borrow`, and `Gc::ptr_eq` in
favor of the more modern equivalents, `box(GC)`, `Deref`, and pointer equality.

The Gc pointer itself should be much more useful now, and subsequent commits
will move the compiler away from @T towards Gc<T>

[breaking-change]

1 files changed, 0 insertions, 7 deletions

diff --git a/src/libcollections/hash/mod.rs b/src/libcollections/hash/mod.rs
index 4220c0b5559..b484b2c8128 100644
--- a/src/libcollections/hash/mod.rs
+++ b/src/libcollections/hash/mod.rs
@@ -248,13 +248,6 @@ impl<S: Writer, T: Hash<S>> Hash<S> for Box<T> {
     }
 }
 
-impl<S: Writer, T: Hash<S>> Hash<S> for @T {
-    #[inline]
-    fn hash(&self, state: &mut S) {
-        (**self).hash(state);
-    }
-}
-
 impl<S: Writer, T: Hash<S>> Hash<S> for Rc<T> {
     #[inline]
     fn hash(&self, state: &mut S) {