Too many changes, without some being really outstanding/major changes, to give a short Summary. The complete Changelog can be found at: https://github.com/nim-lang/Nim/blob/devel/changelogs/changelog_1_4_0.md
There doesn't seem to be any actual changes to my patch, so not sure what the change is all about. Original file should be restored, rebuilt, commit amended and diff updated. Otherwise LGTM.