rustc: Obsolete the `@` syntax entirely

This removes all remnants of `@` pointers from rustc. Additionally, this removes
the `GC` structure from the prelude as it seems odd exporting an experimental
type in the prelude by default.

Closes #14193
[breaking-change]

1 files changed, 2 insertions, 1 deletions

diff --git a/src/test/run-pass/nullable-pointer-iotareduction.rs b/src/test/run-pass/nullable-pointer-iotareduction.rs
index 0e185c3a335..8b26ece176d 100644
--- a/src/test/run-pass/nullable-pointer-iotareduction.rs
+++ b/src/test/run-pass/nullable-pointer-iotareduction.rs
@@ -11,6 +11,7 @@
 #![feature(macro_rules, managed_boxes)]
 
 use std::{option, mem};
+use std::gc::{Gc, GC};
 
 // Iota-reduction is a rule in the Calculus of (Co-)Inductive Constructions,
 // which "says that a destructor applied to an object built from a constructor
@@ -75,7 +76,7 @@ macro_rules! check_type {
 pub fn main() {
     check_type!(&17: &int);
     check_type!(box 18: Box<int>);
-    check_type!(@19: @int);
+    check_type!(box(GC) 19: Gc<int>);
     check_type!("foo".to_string(): String);
     check_type!(vec!(20, 22): Vec<int> );
     let mint: uint = unsafe { mem::transmute(main) };