[release] Add release notes for 2.10.3

Change-Id: I23f85662df75a206f08e5855b1b3b3aadf6be91a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/169201
Reviewed-by: Michael Thomsen <[email protected]>

Author: athomas

CHANGELOG.md

@@ -1,4 +1,25 @@
-## 2.10.2 - 2020-10-13
+## 2.10.3 - 2020-10-29
+
+This is a patch release that fixes the following issues:
+* breaking changes in Chrome 86 that affect DDC (issues [#43750][] and
+  [#43193][]).
+* compiler error causing incorrect use of positional parameters when named
+  parameters should be used instead (issues [flutter/flutter#65324][] and
+  [flutter/flutter#68092][]).
+* crashes and/or undefined behavor in AOT compiled code (issues [#43770][] and
+  [#43786][]).
+* AOT compilation of classes with more than 64 unboxed fields
+  (issue [flutter/flutter#67803][]).
+
+[#43750]: https://github.com/dart-lang/sdk/issues/43750
+[#43193]: https://github.com/dart-lang/sdk/issues/43193
+[flutter/flutter#65324]: https://github.com/flutter/flutter/issues/65324
+[flutter/flutter#68092]: https://github.com/flutter/flutter/issues/68092
+[#43770]: https://github.com/dart-lang/sdk/issues/43770
+[#43786]: https://github.com/dart-lang/sdk/issues/43786
+[flutter/flutter#67803]: https://github.com/flutter/flutter/issues/67803
+
+## 2.10.2 - 2020-10-15
 
 This is a patch release that fixes a DDC compiler crash (issue [#43589]).