Add rule about meaning of `inline` with `async`
On lang, we had earlier made a decision about how `inline` should
apply to `async fn`. Let's document that here.
diff --git a/src/attributes/codegen.md b/src/attributes/codegen.md
index 5c7247b..8d79481 100644
--- a/src/attributes/codegen.md
+++ b/src/attributes/codegen.md
@@ -74,6 +74,12 @@
r[attributes.codegen.inline.trait]
When `inline` is applied to a function in a [trait], it applies only to the code of the [default definition].
+r[attributes.codegen.inline.async]
+When `inline` is applied to an [async function] or [async closure], it applies only to the code of the generated `poll` function.
+
+> [!NOTE]
+> For more details, see [Rust issue #129347](https://github.com/rust-lang/rust/issues/129347).
+
r[attributes.codegen.inline.externally-exported]
The `inline` attribute is ignored if the function is externally exported with [`no_mangle`] or [`export_name`].
@@ -764,6 +770,8 @@
[`unused_variables`]: ../../rustc/lints/listing/warn-by-default.html#unused-variables
[associated functions]: items.associated.fn
[async blocks]: expr.block.async
+[async closure]: expr.closure.async
+[async function]: items.fn.async
[attribute]: ../attributes.md
[attributes]: ../attributes.md
[bodies]: items.fn.body
