[trufas]

Every couple years they'll define an edition of a language (e.g. rust 2015, rust 2018), the idea being that if you choose to stick to one of them, the latest rust will still compile your code as long as you tell it what version you're targetting.

[JoshTriplett]

This isn't related to editions; asm was never stable syntax and couldn't be used in the stable compiler; you could only use it on nightly and only if you opted in. This new syntax is something we hope to stabilize eventually.