[llvm] [IR][AArch64] Add "ptrauth(...)" Constant to represent signed pointers. (PR #85738)

[Nikita Popov via llvm-commits]

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@@ -6993,6 +6997,9 @@ static bool isGuaranteedNotToBeUndefOrPoison(
         isa<ConstantPointerNull>(C) || isa<Function>(C))
       return true;
 
+    if (isa<ConstantPtrAuth>(C))
+      return true;
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nikic wrote:

This doesn't look right, what if the base constant is poison?

https://github.com/llvm/llvm-project/pull/85738