Zig++ 0.17.0-dev.2408+zigpp.ed422e86b

What's Changed

• Metal for std.gpu: the air64 target, .metallib output, and std.gpu.metal by @mattneel in #15
• doc: Apple GPUs, and CI as it runs now by @mattneel in #16
• ci, release: a newer push cancels the older run; docs pushes release nothing by @mattneel in #17
• std: Apple GPU kernels compile without a panic handler of their own by @mattneel in #19

Full Changelog: zigpp-0.17.0-dev.2391...zigpp-0.17.0-dev.2408