[llvm] [hwasan] Add intrinsics for fixed shadow on Aarch64 (PR #89319)

[Vitaly Buka via llvm-commits]

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@@ -67,6 +67,8 @@ enum { RuntimeMask = 0xffff };
 
 } // namespace HWASanAccessInfo
 
+std::optional<unsigned long long> getFixedShadowBase(void);
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vitalybuka wrote:

uint64_t ?

https://github.com/llvm/llvm-project/pull/89319