[llvm] [X86][APX] Fix per-function V3 unwind for EGPR functions on Windows x64 (PR #212924)

[Phoebe Wang via llvm-commits]

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@@ -408,6 +409,12 @@ FunctionPass *createX86LowerAMXIntrinsicsLegacyPass();
 /// Capacity check and sub-fragment splitting for Win x64 Unwind V3.
 FunctionPass *createX86WinEHUnwindV3Pass();
 
+/// Returns true when \p MF must use Windows x64 Unwind V3: the module is in V3
+/// mode, or the function needs an unwind table and may use EGPR (R16-R31),
+/// which V1/V2 cannot encode. Shared by frame lowering and the WinEH Unwind
+/// V2/V3 passes so their decisions cannot disagree.
+bool requiresWinX64UnwindV3(const MachineFunction &MF);
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phoebewang wrote:

```suggestion
bool requireWinX64UnwindV3(const MachineFunction &MF);
```

https://github.com/llvm/llvm-project/pull/212924