ppc: fix FCTIWUZ simulation

Change-Id: Ic4c295265162f5dbc7c425d5e196a1cf2c994003
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3164978
Commit-Queue: Junliang Yan <junyan@redhat.com>
Reviewed-by: Milad Fa <mfarazma@redhat.com>
Cr-Commit-Position: refs/heads/main@{#76882}

src/execution/ppc/simulator-ppc.cc

@@ -3640,8 +3640,8 @@ void Simulator::ExecuteGeneric(Instruction* instr) {
                      ? kRoundToZero
                      : (fp_condition_reg_ & kFPRoundingModeMask);
       uint64_t frt_val;
-      uint64_t kMinVal = 0;
-      uint64_t kMaxVal = kMinVal - 1;
+      uint64_t kMinVal = kMinUInt32;
+      uint64_t kMaxVal = kMaxUInt32;
       bool invalid_convert = false;
 
       if (std::isnan(frb_val)) {