[llvm] [clang] [RISCV] Add Zicfiss support to the shadow call stack implementation. (PR #68075)

[Yeting Kuo via cfe-commits]

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@@ -51,9 +51,15 @@ static void emitSCSPrologue(MachineFunction &MF, MachineBasicBlock &MBB,
           CSI, [&](CalleeSavedInfo &CSR) { return CSR.getReg() == RAReg; }))
     return;
 
+  const RISCVInstrInfo *TII = STI.getInstrInfo();
+  if (!STI.hasForcedSWShadowStack() &&
+      STI.hasFeature(RISCV::FeatureStdExtZicfiss)) {
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yetingk wrote:

Done.

https://github.com/llvm/llvm-project/pull/68075