[clang] [llvm] [AArch64][SME] Save VG for unwind info when changing streaming-mode (PR #83301)

[Eli Friedman via cfe-commits]

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@@ -8287,6 +8289,13 @@ AArch64TargetLowering::LowerCall(CallLoweringInfo &CLI,
 
   SDValue InGlue;
   if (RequiresSMChange) {
+
+    if (Subtarget->hasSVE()) {
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efriedma-quic wrote:

Oh, right, there's also that dimension.  I'm not sure I understand the interaction here, but if there's an issue, can we just force on "asynchronous" unwind info in that case?  The point of non-async unwind info isn't that it's a different unwind format; it's just an optimization to reduce the size of the unwind info.

https://github.com/llvm/llvm-project/pull/83301