Bump to 1.23 and update bootstrap

This commit updates the bootstrap compiler, bumps the version to 1.23, updates
Cargo, updates books, and updates crates.io dependencies

src/libstd/lib.rs

@@ -254,6 +254,15 @@
 #![feature(collections_range)]
 #![feature(compiler_builtins_lib)]
 #![feature(const_fn)]
+#![feature(const_max_value)]
+#![feature(const_atomic_bool_new)]
+#![feature(const_atomic_isize_new)]
+#![feature(const_atomic_usize_new)]
+#![feature(const_unsafe_cell_new)]
+#![feature(const_cell_new)]
+#![feature(const_once_new)]
+#![feature(const_ptr_null)]
+#![feature(const_ptr_null_mut)]
 #![feature(core_float)]
 #![feature(core_intrinsics)]
 #![feature(dropck_eyepatch)]
@@ -294,7 +303,7 @@
 #![feature(repr_align)]
 #![feature(repr_simd)]
 #![feature(rustc_attrs)]
-#![cfg_attr(not(stage0), feature(rustc_const_unstable))]
+#![feature(rustc_const_unstable)]
 #![feature(shared)]
 #![feature(sip_hash_13)]
 #![feature(slice_bytes)]
@@ -318,17 +327,7 @@
 #![feature(doc_cfg)]
 #![feature(doc_masked)]
 #![cfg_attr(test, feature(update_panic_count))]
-
-#![cfg_attr(not(stage0), feature(const_max_value))]
-#![cfg_attr(not(stage0), feature(const_atomic_bool_new))]
-#![cfg_attr(not(stage0), feature(const_atomic_isize_new))]
-#![cfg_attr(not(stage0), feature(const_atomic_usize_new))]
-#![cfg_attr(all(not(stage0), windows), feature(const_atomic_ptr_new))]
-#![cfg_attr(not(stage0), feature(const_unsafe_cell_new))]
-#![cfg_attr(not(stage0), feature(const_cell_new))]
-#![cfg_attr(not(stage0), feature(const_once_new))]
-#![cfg_attr(not(stage0), feature(const_ptr_null))]
-#![cfg_attr(not(stage0), feature(const_ptr_null_mut))]
+#![cfg_attr(windows, feature(const_atomic_ptr_new))]
 
 #![default_lib_allocator]
 

src/libstd/sync/once.rs

@@ -156,7 +156,7 @@ struct Finish {
 impl Once {
     /// Creates a new `Once` value.
     #[stable(feature = "once_new", since = "1.2.0")]
-    #[cfg_attr(not(stage0), rustc_const_unstable(feature = "const_once_new"))]
+    #[rustc_const_unstable(feature = "const_once_new")]
     pub const fn new() -> Once {
         Once {
             state: AtomicUsize::new(INCOMPLETE),

src/libstd/thread/local.rs

@@ -190,11 +190,6 @@ macro_rules! __thread_local_inner {
         }
     };
     ($(#[$attr:meta])* $vis:vis $name:ident, $t:ty, $init:expr) => {
-        #[cfg(stage0)]
-        $(#[$attr])* $vis static $name: $crate::thread::LocalKey<$t> =
-            __thread_local_inner!(@key $(#[$attr])* $vis $name, $t, $init);
-
-        #[cfg(not(stage0))]
         $(#[$attr])* $vis const $name: $crate::thread::LocalKey<$t> =
             __thread_local_inner!(@key $(#[$attr])* $vis $name, $t, $init);
     }