Update CHANGELOG.md with descriptions for fixes in 2.4.1

Change-Id: Ide202ea418ccfe860bd408e489a8c81bbc62e7c1
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/112084
Commit-Queue: Martin Kustermann <[email protected]>
Reviewed-by: Alexander Thomas <[email protected]>

Author: mkustermann

CHANGELOG.md

@@ -132,6 +132,22 @@ The Linter was updated to `0.1.96`, which includes:
 Dartdoc was updated to `0.28.4`; this version includes several fixes and is based
 on a newer version of the analyzer package.
 
+## 2.4.1 - 2019-08-07
+
+This is a patch version release which fixes a performance regression in JIT as
+well as a potential crash of our AOT compiler.
+
+### Dart VM
+
+* Working with `Int32List` could cause repeated deoptimizations leading to a big
+  performance regression in JIT mode. The Issue [37551][] was fixed.
+
+* Using a static getter with name `length` could cause a crash in our AOT
+  compiler. The Issue [35121][] was fixed.
+
+[37551]: https://github.com/dart-lang/sdk/issues/37551
+[35121]: https://github.com/dart-lang/sdk/issues/35121
+
 ## 2.4.0 - 2019-06-27
 
 ### Core libraries