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

[Vitaly Buka via llvm-commits]

================
@@ -117,6 +118,7 @@ class AArch64AsmPrinter : public AsmPrinter {
   void LowerPATCHABLE_EVENT_CALL(const MachineInstr &MI, bool Typed);
 
   typedef std::tuple<unsigned, bool, uint32_t> HwasanMemaccessTuple;
----------------
vitalybuka wrote:

std::optional<uint64_t> HwasanFixedShadowBase;  // already  nullopt

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