[beta] Prepare the 1.24.0 beta release

* Update the channel of this release
* Update the bootstrap compiler to the dev artifacts
* Fix compile for last-minute backports

Author: alexcrichton

src/ci/run.sh

@@ -42,7 +42,7 @@ fi
 #
 # FIXME: need a scheme for changing this `nightly` value to `beta` and `stable`
 #        either automatically or manually.
-export RUST_RELEASE_CHANNEL=nightly
+export RUST_RELEASE_CHANNEL=beta
 if [ "$DEPLOY$DEPLOY_ALT" != "" ]; then
   RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --release-channel=$RUST_RELEASE_CHANNEL"
   RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --enable-llvm-static-stdcpp"

src/liballoc/boxed.rs

@@ -300,7 +300,7 @@ impl<T: ?Sized> Box<T> {
                issue = "27730")]
     #[inline]
     pub unsafe fn from_unique(u: Unique<T>) -> Self {
-        Box(u)
+        mem::transmute(u)
     }
 
     /// Consumes the `Box`, returning the wrapped raw pointer.
@@ -362,9 +362,7 @@ impl<T: ?Sized> Box<T> {
                issue = "27730")]
     #[inline]
     pub fn into_unique(b: Box<T>) -> Unique<T> {
-        let unique = b.0;
-        mem::forget(b);
-        unique
+        unsafe { mem::transmute(b) }
     }
 
     /// Consumes and leaks the `Box`, returning a mutable reference,

src/stage0.txt

@@ -12,9 +12,9 @@
 # source tarball for a stable release you'll likely see `1.x.0` for rustc and
 # `0.x.0` for Cargo where they were released on `date`.
 
-date: 2017-11-21
-rustc: beta
-cargo: beta
+date: 2018-01-02
+rustc: 1.23.0
+cargo: 0.24.0
 
 # When making a stable release the process currently looks like:
 #
@@ -34,4 +34,4 @@ cargo: beta
 # looking at a beta source tarball and it's uncommented we'll shortly comment it
 # out.
 
-#dev: 1
+dev: 1