compiler: manually implement DynSend for AtomicBool

The manual `DynSend` implementation for `AtomicPtr` blocks the
auto-implementation for `Atomic<bool>` since both refer to the same type
now. This breakage cannot occur in user code as it depends on `DynSend`
being a custom auto-trait.

Author: joboet

compiler/rustc_data_structures/src/marker.rs

@@ -59,9 +59,10 @@ macro_rules! already_send {
 
 // These structures are already `Send`.
 already_send!(
-    [std::backtrace::Backtrace][std::io::Stdout][std::io::Stderr][std::io::Error][std::fs::File][std::panic::Location<'_>]
-        [rustc_arena::DroplessArena][jobserver_crate::Client][jobserver_crate::HelperThread]
-        [crate::memmap::Mmap][crate::profiling::SelfProfiler][crate::owned_slice::OwnedSlice]
+    [std::sync::atomic::AtomicBool][std::backtrace::Backtrace][std::io::Stdout][std::io::Stderr]
+        [std::io::Error][std::fs::File][std::panic::Location<'_>][rustc_arena::DroplessArena]
+        [jobserver_crate::Client][jobserver_crate::HelperThread][crate::memmap::Mmap]
+        [crate::profiling::SelfProfiler][crate::owned_slice::OwnedSlice]
 );
 
 macro_rules! impl_dyn_send {