[llvm] AArch64: support extended spills in SEH on WoS (PR #166849)

[Eli Friedman via llvm-commits]

https://github.com/efriedma-quic commented:

WoS is Windows on Snapdragon, which is how Qualcomm refers to AArch64 Windows.

https://github.com/llvm/llvm-project/pull/166849