- The attribute is behind a feature gate.
- Error if both #[naked] and #[track_caller] are applied to the same function.
- Error if #[track_caller] is applied to a non-function item.
- Error if ABI is not "rust"
- Error if #[track_caller] is applied to a trait function.

Error codes and descriptions are pending.

Co-Authored-By: Mazdak Farrokhzad <twingoow@gmail.com>

Prevents number collision with another approved PR.

function pointer const parameters.

const_compare_raw_pointers.

Co-Authored-By: varkor <github@varkor.com>

Updates LLVM to pick up the cherry-picked support for correctly
handling exception handling with aggregates passed by value. This will
be necessary to continue to support Emscripten's exception handling
once we switch using Emscripten's LLVM backend. See rust-lang#63649.

Implement (HashMap) Entry::insert as per rust-lang#60142

Implementation of `Entry::insert` as per @SimonSapin's comment on rust-lang#60142. This requires a patch to hashbrown:

```diff
diff --git a/src/rustc_entry.rs b/src/rustc_entry.rs
index fefa5c3..7de8300 100644
--- a/src/rustc_entry.rs
+++ b/src/rustc_entry.rs
@@ -546,6 +546,32 @@ impl<'a, K, V> RustcVacantEntry<'a, K, V> {
         let bucket = self.table.insert_no_grow(self.hash, (self.key, value));
         unsafe { &mut bucket.as_mut().1 }
     }
+
+    /// Sets the value of the entry with the RustcVacantEntry's key,
+    /// and returns a RustcOccupiedEntry.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use hashbrown::HashMap;
+    /// use hashbrown::hash_map::RustcEntry;
+    ///
+    /// let mut map: HashMap<&str, u32> = HashMap::new();
+    ///
+    /// if let RustcEntry::Vacant(v) = map.rustc_entry("poneyland") {
+    ///     let o = v.insert_and_return(37);
+    ///     assert_eq!(o.get(), &37);
+    /// }
+    /// ```
+     #[inline]
+    pub fn insert_and_return(self, value: V) -> RustcOccupiedEntry<'a, K, V> {
+        let bucket = self.table.insert_no_grow(self.hash, (self.key, value));
+        RustcOccupiedEntry {
+            key: None,
+            elem: bucket,
+            table: self.table
+        }
+    }
 }

 impl<K, V> IterMut<'_, K, V> {
```

This is also only an implementation for HashMap. I tried implementing for BTreeMap, but I don't really understand BTreeMap's internals and require more guidance on implementing the equivalent `VacantEntry::insert_and_return` such that it returns an `OccupiedEntry`. Notably, following the original PR's modifications I end up needing a `Handle<NodeRef<marker::Mut<'_>, _, _, marker::LeafOrInternal>, _>` while I only have a `Handle<NodeRef<marker::Mut<'_>, _, _, marker::Internal>, _>` and don't know how to proceed.

(To be clear, I'm not asking for guidance right now; I'd be happy getting only the HashMap implementation — the subject of this PR — reviewed and ready, and leave the BTreeMap implementation for a latter PR.)

…varkor

Function pointers as const generic arguments

Makes function pointers as const generic arguments usable.

Fixes rust-lang#62395

r? @varkor

`#[track_caller]` feature gate (RFC 2091 1/N)

RFC text: https://github.com/rust-lang/rfcs/blob/master/text/2091-inline-semantic.md
Tracking issue: rust-lang#47809

I started with @ayosec's commit to add the feature gate with tests and rebased it onto current master. I fixed up some tidy lints and added a test.

Suggest to add `move` keyword for generator capture

 Closes rust-lang#64382
r? @estebank

add more info in debug traces for gcu merging

to help in investigation of CGU partitioning problems e.g rust-lang#64913

…exceptions, r=nikic

Update LLVM for Emscripten exception handling support

Updates LLVM to pick up the cherry-picked support for correctly
handling exception handling with aggregates passed by value. This will
be necessary to continue to support Emscripten's exception handling
once we switch using Emscripten's LLVM backend. See rust-lang#63649.