Idle curiosity: once upon a time Wine64 didn't run on Mac, because

OSX has a ABI incompatibility with Win64 - OSX overwrites a CPU register that Win64 applications expect to remain untouched. Apple can’t change the ABI because there are already 64 bit OSX apps that expect things to work that way. A potential workaround may be to run Wine inside a CPU emulator like qemu, but that is anything but easy.

https://www.winehq.org/pipermail/wine-devel/2014-February/103074.html

Yet Wine64 does run on macOS today. Does anyone have a link to what changed and when? Was it Apple bending to support Wine (or more likely CrossOver), or Wine manually preserving the register, or something else?

(Presumably the answer is also somewhere on the Wine mailing lists…)