Add @Since annotation, correct changelog entry position.

CoreLibraryReviewExempt: Trivial change.
Change-Id: I5c23641ed562efe51c0c7c35517ba75fffdd05ad
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/372503
Reviewed-by: Kevin Moore <kevmoo@google.com>
Commit-Queue: Lasse Nielsen <lrn@google.com>

CHANGELOG.md

@@ -34,11 +34,6 @@
   (`add`, `subtract`, `difference`) where the `Duration` argument or result
   exceeds 570 years.
 
-- Added superinterface `TypedDataList` to typed data lists, implementing both
-  `List` and `TypedData`. Allows abstracting over all such lists without losing
-  access to either the `List` or the `TypedData` members.
-  A `ByteData` is still only a `TypedData`, not a list.
-
 [#44876]: https://github.com/dart-lang/sdk/issues/44876
 
 #### `dart:typed_data`
@@ -49,6 +44,11 @@
   To create an unmodifiable view of a typed-data object, use the
   `asUnmodifiableView()` methods added in Dart 3.3.
 
+- Added superinterface `TypedDataList` to typed data lists, implementing both
+  `List` and `TypedData`. Allows abstracting over all such lists without losing
+  access to either the `List` or the `TypedData` members.
+  A `ByteData` is still only a `TypedData`, not a list.
+
 [#53785]: https://github.com/dart-lang/sdk/issues/53785
 
 ### Tools

sdk/lib/typed_data/typed_data.dart

@@ -359,6 +359,7 @@ abstract final class TypedData {
 }
 
 /// A [TypedData] fixed-length [List]-view on the bytes of [buffer].
+@Since("3.5")
 abstract final class TypedDataList<E> implements TypedData, List<E> {}
 
 abstract final class _TypedIntList implements TypedDataList<int> {