Add changelog for 3.2.0-RC2

Author: Kordyjan

changelogs/3.2.0-RC2.md

@@ -0,0 +1,22 @@
+# Backported fixes
+
+- Handle non-specialized functions in EtaReduce [#15498](https://github.com/lampepfl/dotty/pull/15498)
+- Refine Matchtype checking [#15423](https://github.com/lampepfl/dotty/pull/15423)
+- Fix lifting of arguments with `-coverage-out` [#15530](https://github.com/lampepfl/dotty/pull/15530)
+- Avoid instrumentation of inline and erased definitions [#15504](https://github.com/lampepfl/dotty/pull/15504)
+- Irrefutable for generators don't require `withFilter` under `-source:future` [#15593](https://github.com/lampepfl/dotty/pull/15593)
+
+# Contributors
+
+Thank you to all the contributors who made this release possible 🎉
+
+According to `git shortlog -sn --no-merges 3.2.0-RC1..3.2.0-RC2` these are:
+
+```
+     4  Guillaume Raffin
+     4  odersky
+     2  Paweł Marks
+     1  Nicolas Stucki
+     1  Sébastien Doeraene
+     1  Tom Grigg
+```