Add v3.16.5 to CHANGELOG.md.

Author: Robert Jackson

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Ember Changelog
 
+### v3.16.5 (March 23, 2020)
+
+- [#18831](https://github.com/emberjs/ember.js/pull/18831) [BUGFIX] Fix transpilation issues (e.g. `_createSuper` is not a function) when used with Babel 7.9.0+.
+
 ### v3.16.4 (March 22, 2020)
 
 - [#18741](https://github.com/emberjs/ember.js/pull/18741) [BUGFIX] Don't setup mandatory setters on array indexes