Register new snapshots

This change starts denying `*T` in the parser. All code using `*T` should ensure
that the FFI call does indeed take `const T*` on the other side before renaming
the type to `*const T`.

Otherwise, all code can rename `*T` to `*const T`.

[breaking-change]

src/liballoc/lib.rs

@@ -70,7 +70,6 @@
 
 #![no_std]
 #![feature(lang_items, phase, unsafe_destructor)]
-#![allow(unknown_features)] // NOTE: remove after a stage0 snap
 
 #[phase(plugin, link)]
 extern crate core;