I often come across bug tickets like this one, and anxiously await the release of their fixes. But there isn't anywhere that I can find where there's a comprehensive list of all the Swift bug fixes that actually ship with the version of Swift that gets bundled with any given Xcode release. It's my understanding that the open-source releases of "Swift v.N" don't necessarily correspond, commit-for-commit, with the "Swift v.N" as announced in the release notes for new Xcode releases.
I understand that Swift isn't intended solely for use with Xcode. But in practice, Xcode is the de facto official IDE for many Swift developers. So much so that, for example, the claim that "we're using Swift 5 now" is very often equivalent to saying "we're using Xcode 10.2 with the Swift compiler version bumped to 5."
Given how central Xcode is to real-world use of Swift, and how tightly integrated Xcode releases are with Swift compiler releases, there should be a way -- a web page, a README, a tag on the bug tracker site, etc. -- a way to see which specific tasks, referenced by an
SR-NNNN ticket number or a link to said ticket, actually ship with the Swift version bundled with Xcode.