Arm64: Don't clobber NZCV in CondJump

Again we need to handle this one specially because the dispatcher can't insert
restore code after the branch. It should be optimized in the near future, don't
worry.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>

FEXCore/Source/Interface/Core/JIT/Arm64/BranchOps.cpp

@@ -145,6 +145,9 @@ DEF_OP(CondJump) {
     LOGMAN_THROW_A_FMT(IsGPR(Op->Cmp1.ID()), "CondJump: Expected GPR");
     cbnz(Size, GetReg(Op->Cmp1.ID()), TrueTargetLabel);
   } else {
+    // FIXME: We should split up this op to avoid the NZCV spill/fill dance.
+    mrs(TMP1, ARMEmitter::SystemRegister::NZCV);
+
     if (IsGPR(Op->Cmp1.ID())) {
       if (tests) {
         if (isConst) {
@@ -165,7 +168,12 @@ DEF_OP(CondJump) {
       LOGMAN_MSG_A_FMT("CondJump: Expected GPR or FPR");
     }
 
-    b(MapBranchCC(Op->Cond), TrueTargetLabel);
+    // Restore NZCV
+    cset(Size, TMP2, MapBranchCC(Op->Cond));
+    msr(ARMEmitter::SystemRegister::NZCV, TMP1);
+
+    // Non-NZCV using branch so we can keep the guest value
+    cbnz(Size, TMP2, TrueTargetLabel);
   }
 
   PendingTargetLabel = &JumpTargets.try_emplace(Op->FalseBlock.ID()).first->second;