[clang] [PAC] Implement function pointer re-signing (PR #98847)

[Akira Hatanaka via cfe-commits]

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@@ -165,6 +166,88 @@ CGPointerAuthInfo CodeGenModule::getPointerAuthInfoForType(QualType T) {
   return ::getPointerAuthInfoForType(*this, T);
 }
 
+static bool isZeroConstant(llvm::Value *value) {
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ahatanak wrote:

I fixed the names of variables and functions added in this PR.

https://github.com/llvm/llvm-project/pull/98847