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-size.rs b/src/test/run-pass/nullable-pointer-size.rs
index 2309984a1f1..8a54f22585f 100644
--- a/src/test/run-pass/nullable-pointer-size.rs
+++ b/src/test/run-pass/nullable-pointer-size.rs
@@ -11,6 +11,7 @@
 #![feature(macro_rules, managed_boxes)]
 
 use std::mem;
+use std::gc::Gc;
 
 enum E<T> { Thing(int, T), Nothing((), ((), ()), [i8, ..0]) }
 struct S<T>(int, T);
@@ -39,6 +40,6 @@ macro_rules! check_type {
 pub fn main() {
     check_type!(&'static int);
     check_type!(Box<int>);
-    check_type!(@int);
+    check_type!(Gc<int>);
     check_type!(extern fn());
 }