Auto merge of #108709 - matthiaskrgr:rollup-j2tjbyx, r=matthiaskrgr

Rollup of 8 pull requests

Successful merges:

 - #104549 (add -Zexport-executable-symbols to unstable book)
 - #108292 (Label opaque type for 'captures lifetime' error message)
 - #108540 (Add `Atomic*::from_ptr`)
 - #108634 (Add link to component dashboard)
 - #108647 (Remove dead pgo.sh file)
 - #108678 (Use `Option::as_slice` where applicable)
 - #108681 (Improve comments in `needs_process_obligation`.)
 - #108688 (Match unmatched backticks in library/)

Failed merges:

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

compiler/rustc_data_structures/src/obligation_forest/mod.rs

@@ -426,6 +426,7 @@ impl<O: ForestObligation> ObligationForest<O> {
             // nodes. Therefore we use a `while` loop.
             let mut index = 0;
             while let Some(node) = self.nodes.get_mut(index) {
+                // This test is extremely hot.
                 if node.state.get() != NodeState::Pending
                     || !processor.needs_process_obligation(&node.obligation)
                 {
@@ -439,6 +440,7 @@ impl<O: ForestObligation> ObligationForest<O> {
                 // out of sync with `nodes`. It's not very common, but it does
                 // happen, and code in `compress` has to allow for it.
 
+                // This code is much less hot.
                 match processor.process_obligation(&mut node.obligation) {
                     ProcessResult::Unchanged => {
                         // No change in state.