Auto merge of #76964 - RalfJung:rollup-ybn06fs, r=RalfJung

Rollup of 15 pull requests

Successful merges:

 - #76722 (Test and fix Send and Sync traits of BTreeMap artefacts)
 - #76766 (Extract some intrinsics out of rustc_codegen_llvm)
 - #76800 (Don't generate bootstrap usage unless it's needed)
 - #76809 (simplfy condition in ItemLowerer::with_trait_impl_ref())
 - #76815 (Fix wording in mir doc)
 - #76818 (Don't compile regex at every function call.)
 - #76821 (Remove redundant nightly features)
 - #76823 (black_box: silence unused_mut warning when building with cfg(miri))
 - #76825 (use `array_windows` instead of `windows` in the compiler)
 - #76827 (fix array_windows docs)
 - #76828 (use strip_prefix over starts_with and manual slicing based on pattern length (clippy::manual_strip))
 - #76840 (Move to intra doc links in core/src/future)
 - #76845 (Use intra docs links in core::{ascii, option, str, pattern, hash::map})
 - #76853 (Use intra-doc links in library/core/src/task/wake.rs)
 - #76871 (support panic=abort in Miri)

Failed merges:

r? `@ghost`

compiler/rustc_arena/src/lib.rs

@@ -11,7 +11,6 @@
     html_root_url = "https://doc.rust-lang.org/nightly/",
     test(no_crate_inject, attr(deny(warnings)))
 )]
-#![feature(core_intrinsics)]
 #![feature(dropck_eyepatch)]
 #![feature(new_uninit)]
 #![feature(maybe_uninit_slice)]
@@ -24,7 +23,6 @@ use smallvec::SmallVec;
 use std::alloc::Layout;
 use std::cell::{Cell, RefCell};
 use std::cmp;
-use std::intrinsics;
 use std::marker::{PhantomData, Send};
 use std::mem::{self, MaybeUninit};
 use std::ptr;
@@ -122,7 +120,7 @@ impl<T> TypedArena<T> {
 
         unsafe {
             if mem::size_of::<T>() == 0 {
-                self.ptr.set(intrinsics::arith_offset(self.ptr.get() as *mut u8, 1) as *mut T);
+                self.ptr.set((self.ptr.get() as *mut u8).wrapping_offset(1) as *mut T);
                 let ptr = mem::align_of::<T>() as *mut T;
                 // Don't drop the object. This `write` is equivalent to `forget`.
                 ptr::write(ptr, object);

compiler/rustc_ast/src/lib.rs

@@ -5,17 +5,13 @@
 //! This API is completely unstable and subject to change.
 
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/", test(attr(deny(warnings))))]
-#![feature(bool_to_option)]
 #![feature(box_syntax)]
 #![feature(const_fn)] // For the `transmute` in `P::new`
 #![feature(const_panic)]
-#![feature(const_fn_transmute)]
 #![feature(crate_visibility_modifier)]
 #![feature(label_break_value)]
 #![feature(nll)]
 #![feature(or_patterns)]
-#![feature(try_trait)]
-#![feature(unicode_internals)]
 #![recursion_limit = "256"]
 
 #[macro_use]

compiler/rustc_ast_lowering/src/item.rs

@@ -27,7 +27,7 @@ pub(super) struct ItemLowerer<'a, 'lowering, 'hir> {
 impl ItemLowerer<'_, '_, '_> {
     fn with_trait_impl_ref(&mut self, impl_ref: &Option<TraitRef>, f: impl FnOnce(&mut Self)) {
         let old = self.lctx.is_in_trait_impl;
-        self.lctx.is_in_trait_impl = if let &None = impl_ref { false } else { true };
+        self.lctx.is_in_trait_impl = impl_ref.is_some();
         f(self);
         self.lctx.is_in_trait_impl = old;
     }