Auto merge of rust-lang#117272 - matthiaskrgr:rollup-upg122z, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - rust-lang#114998 (feat(docs): add cargo-pgo to PGO documentation 📝)
 - rust-lang#116868 (Tweak suggestion span for outer attr and point at item following invalid inner attr)
 - rust-lang#117240 (Fix documentation typo in std::iter::Iterator::collect_into)
 - rust-lang#117241 (Stash and cancel cycle errors for auto trait leakage in opaques)
 - rust-lang#117262 (Create a new ConstantKind variant (ZeroSized) for StableMIR)
 - rust-lang#117266 (replace transmute by raw pointer cast)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

core/src/iter/traits/iterator.rs

@@ -2142,7 +2142,7 @@ pub trait Iterator {
     /// passed collection. The collection is then returned, so the call chain
     /// can be continued.
     ///
-    /// This is useful when you already have a collection and wants to add
+    /// This is useful when you already have a collection and want to add
     /// the iterator items to it.
     ///
     /// This method is a convenience method to call [Extend::extend](trait.Extend.html),

std/src/thread/mod.rs

@@ -545,6 +545,13 @@ impl Builder {
             scope_data.increment_num_running_threads();
         }
 
+        let main = Box::new(main);
+        #[cfg(bootstrap)]
+        let main =
+            unsafe { mem::transmute::<Box<dyn FnOnce() + 'a>, Box<dyn FnOnce() + 'static>>(main) };
+        #[cfg(not(bootstrap))]
+        let main = unsafe { Box::from_raw(Box::into_raw(main) as *mut (dyn FnOnce() + 'static)) };
+
         Ok(JoinInner {
             // SAFETY:
             //
@@ -559,14 +566,7 @@ impl Builder {
             // Similarly, the `sys` implementation must guarantee that no references to the closure
             // exist after the thread has terminated, which is signaled by `Thread::join`
             // returning.
-            native: unsafe {
-                imp::Thread::new(
-                    stack_size,
-                    mem::transmute::<Box<dyn FnOnce() + 'a>, Box<dyn FnOnce() + 'static>>(
-                        Box::new(main),
-                    ),
-                )?
-            },
+            native: unsafe { imp::Thread::new(stack_size, main)? },
             thread: my_thread,
             packet: my_packet,
         })