diff --git a/Readme.md b/Readme.md
index 1bad1e71137..95fc6374c09 100644
--- a/Readme.md
+++ b/Readme.md
@@ -292,7 +292,7 @@ To send the changes to the rust repo:
 ```bash
 cd ../rust
 git pull origin master
-git checkbout -b subtree-update_cg_gcc_YYYY-MM-DD
+git checkout -b subtree-update_cg_gcc_YYYY-MM-DD
 PATH="$HOME/bin:$PATH" ~/bin/git-subtree pull --prefix=compiler/rustc_codegen_gcc/ https://github.com/rust-lang/rustc_codegen_gcc.git master
 git push
 ```
diff --git a/example/std_example.rs b/example/std_example.rs
index 2d57866c1d1..0f6325c8980 100644
--- a/example/std_example.rs
+++ b/example/std_example.rs
@@ -1,10 +1,10 @@
-#![feature(core_intrinsics, generators, generator_trait, is_sorted)]
+#![feature(core_intrinsics, coroutines, coroutine_trait, is_sorted)]
 
 #[cfg(feature="master")]
 #[cfg(target_arch="x86_64")]
 use std::arch::x86_64::*;
 use std::io::Write;
-use std::ops::Generator;
+use std::ops::Coroutine;
 
 extern {
     pub fn printf(format: *const i8, ...) -> i32;
diff --git a/failing-non-lto-tests.txt b/failing-non-lto-tests.txt
index 2f338f7d3c8..4fd60f2b8e4 100644
--- a/failing-non-lto-tests.txt
+++ b/failing-non-lto-tests.txt
@@ -5,7 +5,7 @@ tests/ui/lto/lto-many-codegen-units.rs
 tests/ui/lto/issue-100772.rs
 tests/ui/lto/lto-rustc-loads-linker-plugin.rs
 tests/ui/panic-runtime/lto-unwind.rs
-tests/ui/sanitize/issue-111184-generator-witness.rs
+tests/ui/sanitize/issue-111184-coroutine-witness.rs
 tests/ui/sepcomp/sepcomp-lib-lto.rs
 tests/ui/lto/lto-opt-level-s.rs
 tests/ui/lto/lto-opt-level-z.rs
diff --git a/failing-ui-tests.txt b/failing-ui-tests.txt
index 771da581295..22044eabe96 100644
--- a/failing-ui-tests.txt
+++ b/failing-ui-tests.txt
@@ -21,8 +21,8 @@ tests/ui/cfg/cfg-panic-abort.rs
 tests/ui/drop/dynamic-drop-async.rs
 tests/ui/drop/repeat-drop.rs
 tests/ui/fmt/format-args-capture.rs
-tests/ui/generator/panic-drops-resume.rs
-tests/ui/generator/panic-drops.rs
+tests/ui/coroutine/panic-drops-resume.rs
+tests/ui/coroutine/panic-drops.rs
 tests/ui/intrinsics/panic-uninitialized-zeroed.rs
 tests/ui/iterators/iter-sum-overflow-debug.rs
 tests/ui/iterators/iter-sum-overflow-overflow-checks.rs
@@ -53,7 +53,7 @@ tests/ui/simd/issue-89193.rs
 tests/ui/statics/issue-91050-1.rs
 tests/ui/statics/issue-91050-2.rs
 tests/ui/alloc-error/default-alloc-error-hook.rs
-tests/ui/generator/panic-safe.rs
+tests/ui/coroutine/panic-safe.rs
 tests/ui/issues/issue-14875.rs
 tests/ui/issues/issue-29948.rs
 tests/ui/panics/nested_panic_caught.rs
@@ -70,5 +70,5 @@ tests/ui/lto/lto-thin-rustc-loads-linker-plugin.rs
 tests/ui/lto/all-crates.rs
 tests/ui/async-await/deep-futures-are-freeze.rs
 tests/ui/closures/capture-unsized-by-ref.rs
-tests/ui/generator/resume-after-return.rs
+tests/ui/coroutine/resume-after-return.rs
 tests/ui/macros/rfc-2011-nicer-assert-messages/all-expr-kinds.rs
diff --git a/failing-ui-tests12.txt b/failing-ui-tests12.txt
index f027afa78a3..f91aa925318 100644
--- a/failing-ui-tests12.txt
+++ b/failing-ui-tests12.txt
@@ -28,7 +28,7 @@ tests/ui/rfcs/rfc-1937-termination-trait/termination-trait-in-test.rs
 tests/ui/async-await/async-fn-size-moved-locals.rs
 tests/ui/async-await/async-fn-size-uninit-locals.rs
 tests/ui/cfg/cfg-panic.rs
-tests/ui/generator/size-moved-locals.rs
+tests/ui/coroutine/size-moved-locals.rs
 tests/ui/macros/rfc-2011-nicer-assert-messages/all-not-available-cases.rs
 tests/ui/simd/intrinsic/generic-gather-pass.rs
 tests/ui/simd/issue-85915-simd-ptrs.rs
diff --git a/rust-toolchain b/rust-toolchain
index 25a1cea98cc..205ec53b425 100644
--- a/rust-toolchain
+++ b/rust-toolchain
@@ -1,3 +1,3 @@
 [toolchain]
-channel = "nightly-2023-10-08"
+channel = "nightly-2023-10-21"
 components = ["rust-src", "rustc-dev", "llvm-tools-preview"]
diff --git a/src/base.rs b/src/base.rs
index 3152357fe49..5073066c138 100644
--- a/src/base.rs
+++ b/src/base.rs
@@ -121,7 +121,7 @@ pub fn compile_codegen_unit(tcx: TyCtxt<'_>, cgu_name: Symbol, target_info: Lock
         // NOTE: Rust relies on LLVM doing wrapping on overflow.
         context.add_command_line_option("-fwrapv");
 
-        if tcx.sess.opts.cg.relocation_model == Some(rustc_target::spec::RelocModel::Static) {
+        if tcx.sess.relocation_model() == rustc_target::spec::RelocModel::Static {
             context.add_command_line_option("-mcmodel=kernel");
             context.add_command_line_option("-fno-pie");
         }
diff --git a/src/lib.rs b/src/lib.rs
index 2355cd1f696..a530fc994a2 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -12,6 +12,9 @@
  * TODO(antoyo): remove the patches.
  */
 
+#![cfg_attr(not(bootstrap), allow(internal_features))]
+#![cfg_attr(not(bootstrap), doc(rust_logo))]
+#![cfg_attr(not(bootstrap), feature(rustdoc_internals))]
 #![feature(
     rustc_private,
     decl_macro,
@@ -73,6 +76,7 @@ mod type_;
 mod type_of;
 
 use std::any::Any;
+use std::fmt::Debug;
 use std::sync::Arc;
 use std::sync::Mutex;
 #[cfg(not(feature="master"))]
@@ -93,6 +97,7 @@ use rustc_codegen_ssa::back::write::{CodegenContext, FatLtoInput, ModuleConfig,
 use rustc_codegen_ssa::back::lto::{LtoModuleCodegen, SerializedModule, ThinModule};
 use rustc_codegen_ssa::target_features::supported_target_features;
 use rustc_data_structures::fx::FxIndexMap;
+use rustc_data_structures::sync::IntoDynSyncSend;
 use rustc_codegen_ssa::traits::{CodegenBackend, ExtraBackendMethods, ThinBufferMethods, WriteBackendMethods};
 use rustc_errors::{DiagnosticMessage, ErrorGuaranteed, Handler, SubdiagnosticMessage};
 use rustc_fluent_macro::fluent_messages;
@@ -138,9 +143,15 @@ impl TargetInfo {
     }
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone)]
 pub struct LockedTargetInfo {
-    info: Arc<Mutex<TargetInfo>>,
+    info: Arc<Mutex<IntoDynSyncSend<TargetInfo>>>,
+}
+
+impl Debug for LockedTargetInfo {
+    fn fmt(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        self.info.lock().expect("lock").fmt(formatter)
+    }
 }
 
 impl LockedTargetInfo {
@@ -174,7 +185,7 @@ impl CodegenBackend for GccCodegenBackend {
                 context.add_command_line_option(&format!("-march={}", target_cpu));
             }
 
-            *self.target_info.info.lock().expect("lock") = context.get_target_info();
+            **self.target_info.info.lock().expect("lock") = context.get_target_info();
         }
 
         #[cfg(feature="master")]
@@ -341,12 +352,12 @@ pub fn __rustc_codegen_backend() -> Box<dyn CodegenBackend> {
     let info = {
         // Check whether the target supports 128-bit integers.
         let context = Context::default();
-        Arc::new(Mutex::new(context.get_target_info()))
+        Arc::new(Mutex::new(IntoDynSyncSend(context.get_target_info())))
     };
     #[cfg(not(feature="master"))]
-    let info = Arc::new(Mutex::new(TargetInfo {
+    let info = Arc::new(Mutex::new(IntoDynSyncSend(TargetInfo {
         supports_128bit_integers: AtomicBool::new(false),
-    }));
+    })));
 
     Box::new(GccCodegenBackend {
         target_info: LockedTargetInfo { info },
diff --git a/src/type_of.rs b/src/type_of.rs
index 1189e96e308..479a814788a 100644
--- a/src/type_of.rs
+++ b/src/type_of.rs
@@ -87,7 +87,7 @@ fn uncached_gcc_type<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, layout: TyAndLayout
         // FIXME(eddyb) producing readable type names for trait objects can result
         // in problematically distinct types due to HRTB and subtyping (see #47638).
         // ty::Dynamic(..) |
-        ty::Adt(..) | ty::Closure(..) | ty::Foreign(..) | ty::Generator(..) | ty::Str
+        ty::Adt(..) | ty::Closure(..) | ty::Foreign(..) | ty::Coroutine(..) | ty::Str
             if !cx.sess().fewer_names() =>
         {
             let mut name = with_no_trimmed_paths!(layout.ty.to_string());
@@ -98,10 +98,10 @@ fn uncached_gcc_type<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, layout: TyAndLayout
                     write!(&mut name, "::{}", def.variant(index).name).unwrap();
                 }
             }
-            if let (&ty::Generator(_, _, _), &Variants::Single { index }) =
+            if let (&ty::Coroutine(_, _, _), &Variants::Single { index }) =
                 (layout.ty.kind(), &layout.variants)
             {
-                write!(&mut name, "::{}", ty::GeneratorArgs::variant_name(index)).unwrap();
+                write!(&mut name, "::{}", ty::CoroutineArgs::variant_name(index)).unwrap();
             }
             Some(name)
         }
diff --git a/test.sh b/test.sh
index 2eceee7c1e9..fa34c31dbaa 100755
--- a/test.sh
+++ b/test.sh
@@ -371,10 +371,10 @@ function test_rustc() {
 
     git checkout -- tests/ui/issues/auxiliary/issue-3136-a.rs # contains //~ERROR, but shouldn't be removed
 
-    rm -r tests/ui/{abi*,extern/,unsized-locals/,proc-macro/,threads-sendsync/,thinlto/,borrowck/,chalkify/bugs/,test*,consts/const-float-bits-reject-conv.rs,consts/issue-miri-1910.rs} || true
+    rm -r tests/ui/{abi*,extern/,unsized-locals/,proc-macro/,threads-sendsync/,borrowck/,test*,consts/issue-miri-1910.rs} || true
     rm tests/ui/mir/mir_heavy_promoted.rs # this test is oom-killed in the CI.
     # Tests generating errors.
-    rm tests/ui/consts/const-eval/nonnull_as_ref_ub.rs tests/ui/consts/issue-94675.rs
+    rm tests/ui/consts/issue-94675.rs
     for test in $(rg --files-with-matches "thread" tests/ui); do
       rm $test
     done