[llvm] [AArch64] Accept __chkstk_darwin stack probes on Darwin (PR #210812)

[Karim Alweheshy via llvm-commits]

karim-alweheshy wrote:

@aemerson @ahatanak Gentle follow-up: could one of you review whether accepting Apple Swift’s `__chkstk_darwin` spelling on Darwin by using AArch64’s existing inline probe sequence is the right upstream handling? The PR remains conflict-free and exact-head CI is green. Thanks!

https://github.com/llvm/llvm-project/pull/210812