[llvm] [AArch64] Codegen for AArch64 Return Address Signing Hardening (PR #176187)

[Anatoly Trosinenko via llvm-commits]

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@@ -190,6 +190,12 @@ class AArch64FunctionInfo final : public MachineFunctionInfo {
   /// epilogue when using PC as a second salt (FEAT_PAuth_LR)
   MCSymbol *SignInstrLabel = nullptr;
 
+  /// SignReturnAddressHardening specifies the PAC-RET hardening scheme.
+  enum class SignReturnAddressHardeningKind {
+    None,
+    LoadReturnAddress
+  } SignReturnAddressHardening = SignReturnAddressHardeningKind::None;
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atrosinenko wrote:

[nit] I would split type definition and variable declaration for better readability (feel free to ignore).

https://github.com/llvm/llvm-project/pull/176187