Auto merge of rust-lang#132145 - RalfJung:stdarch, r=Amanieu

bump stdarch

This lets us remove a hack from rust-lang#131349.

r? `@Amanieu`

try-job: test-various

std/src/sys/sync/condvar/no_threads.rs

@@ -5,7 +5,7 @@ pub struct Condvar {}
 
 impl Condvar {
     #[inline]
-    #[rustc_const_stable(feature = "const_locks", since = "1.63.0")]
+    #[cfg_attr(bootstrap, rustc_const_stable(feature = "const_locks", since = "1.63.0"))]
     pub const fn new() -> Condvar {
         Condvar {}
     }

std/src/sys/sync/mutex/no_threads.rs

@@ -10,7 +10,7 @@ unsafe impl Sync for Mutex {} // no threads on this platform
 
 impl Mutex {
     #[inline]
-    #[rustc_const_stable(feature = "const_locks", since = "1.63.0")]
+    #[cfg_attr(bootstrap, rustc_const_stable(feature = "const_locks", since = "1.63.0"))]
     pub const fn new() -> Mutex {
         Mutex { locked: Cell::new(false) }
     }

std/src/sys/sync/once/no_threads.rs

@@ -35,7 +35,7 @@ unsafe impl Sync for Once {}
 
 impl Once {
     #[inline]
-    #[rustc_const_stable(feature = "const_once_new", since = "1.32.0")]
+    #[cfg_attr(bootstrap, rustc_const_stable(feature = "const_once_new", since = "1.32.0"))]
     pub const fn new() -> Once {
         Once { state: Cell::new(State::Incomplete) }
     }

std/src/sys/sync/rwlock/no_threads.rs

@@ -10,7 +10,7 @@ unsafe impl Sync for RwLock {} // no threads on this platform
 
 impl RwLock {
     #[inline]
-    #[rustc_const_stable(feature = "const_locks", since = "1.63.0")]
+    #[cfg_attr(bootstrap, rustc_const_stable(feature = "const_locks", since = "1.63.0"))]
     pub const fn new() -> RwLock {
         RwLock { mode: Cell::new(0) }
     }