Revisiting SE-0282: distributing swift-atomics with the toolchain

[taylorswift]

@lorentey

The only thing we achieve by not having synchronization primitives in the Swift Standard Library at this point is the proliferation of half-baked, ill-considered attempts at implementing the same, throughout the entire ecosystem.

thank you Karoy, for the honest assessment of the current state of affairs with multi-platform atomics. unfortunately atomics today only work comprehensively on Apple platforms, and that is inhibiting the development of multi-platform concurrent libraries.

there are two things that can be done right now to improve the multi-platform experience for swift atomics:

1. enabling doublewide atomics on non-Apple platforms (PR), which will allow us to use the official swift-atomics package on linux (instead of a constellation of everyone’s personal forks), and

2. merging this PR, which i am told will allow us to use swift-atomics on Windows.

i really hope to see some movement on these items soon.