Update Rust toolchain to nightly-2023-12-08 (#2926)

Updates the Rust toolchain to `nightly-2023-12-08`. The relevant changes
are:
 * rust-lang/rust#118324
 * rust-lang/rust#118684

---------

Co-authored-by: Celina G. Val <celinval@amazon.com>

kani-compiler/src/codegen_cprover_gotoc/codegen/operand.rs

@@ -421,7 +421,8 @@ impl<'tcx> GotocCtx<'tcx> {
  }
  (Scalar::Ptr(ptr, _size), _) => {
  let res_t = self.codegen_ty(ty);
- let (alloc_id, offset) = ptr.into_parts();
+ let (prov, offset) = ptr.into_parts();
+ let alloc_id = prov.alloc_id();
  self.codegen_alloc_pointer(res_t, alloc_id, offset, span)
  }
  _ => unimplemented!(),
@@ -646,7 +647,8 @@ impl<'tcx> GotocCtx<'tcx> {
  Size::from_bytes(self.symbol_table.machine_model().pointer_width_in_bytes());
 
  let mut next_offset = Size::ZERO;
- for &(offset, alloc_id) in alloc.provenance().ptrs().iter() {
+ for &(offset, prov) in alloc.provenance().ptrs().iter() {
+ let alloc_id = prov.alloc_id();
  if offset > next_offset {
  let bytes = alloc.inspect_with_uninit_and_ptr_outside_interpreter(
  next_offset.bytes_usize()..offset.bytes_usize(),

kani-compiler/src/codegen_cprover_gotoc/codegen/typ.rs

@@ -332,11 +332,11 @@ impl<'tcx> GotocCtx<'tcx> {
  ty: Ty<'tcx>,
  args: ty::GenericArgsRef<'tcx>,
  ) -> ty::PolyFnSig<'tcx> {
- let sig = args.as_coroutine().poly_sig();
+ let sig = args.as_coroutine().sig();
 
- let bound_vars = self.tcx.mk_bound_variable_kinds_from_iter(
- sig.bound_vars().iter().chain(iter::once(ty::BoundVariableKind::Region(ty::BrEnv))),
- );
+ let bound_vars = self.tcx.mk_bound_variable_kinds_from_iter(iter::once(
+ ty::BoundVariableKind::Region(ty::BrEnv),
+ ));
  let br = ty::BoundRegion {
  var: ty::BoundVar::from_usize(bound_vars.len() - 1),
  kind: ty::BoundRegionKind::BrEnv,
@@ -349,7 +349,6 @@ impl<'tcx> GotocCtx<'tcx> {
  let pin_args = self.tcx.mk_args(&[env_ty.into()]);
  let env_ty = Ty::new_adt(self.tcx, pin_adt_ref, pin_args);
 
- let sig = sig.skip_binder();
  // The `FnSig` and the `ret_ty` here is for a coroutines main
  // `coroutine::resume(...) -> CoroutineState` function in case we
  // have an ordinary coroutine, or the `Future::poll(...) -> Poll`

kani-compiler/src/kani_middle/reachability.rs

@@ -153,11 +153,7 @@ impl<'tcx> MonoItemsCollector<'tcx> {
  /// instruction looking for the items that should be included in the compilation.
  fn reachable_items(&mut self) {
  while let Some(to_visit) = self.queue.pop() {
- // TODO: This should only check is_foreign_item() or even `has_body()`.
- // We need https://github.com/rust-lang/rust/pull/118681 to land first.
- if !self.collected.contains(&to_visit)
- && !self.tcx.is_foreign_item(rustc_internal::internal(to_visit.clone()).def_id())
- {
+ if !self.collected.contains(&to_visit) {
  self.collected.insert(to_visit.clone());
  let next_items = match &to_visit {
  MonoItem::Fn(instance) => self.visit_fn(*instance),

rust-toolchain.toml

@@ -2,5 +2,5 @@
 # SPDX-License-Identifier: Apache-2.0 OR MIT
 
 [toolchain]
-channel = "nightly-2023-12-07"
+channel = "nightly-2023-12-08"
 components = ["llvm-tools-preview", "rustc-dev", "rust-src", "rustfmt"]