PPC: [turbofan] Implemented the TruncateFloat64ToUint64 TurboFan operator.

src/ppc/disasm-ppc.cc

Index: src/ppc/disasm-ppc.cc
diff --git a/src/ppc/disasm-ppc.cc b/src/ppc/disasm-ppc.cc
index 918dd0a31f7afed717efe6c50ad1b4fb0857ba57..e99c5af778004b969904dc7ac960c3f10acfaa40 100644
--- a/src/ppc/disasm-ppc.cc
+++ b/src/ppc/disasm-ppc.cc
@@ -961,6 +961,14 @@ void Decoder::DecodeExt4(Instruction* instr) {
       Format(instr, "fctidz  'Dt, 'Db");
       break;
     }
+    case FCTIDU: {
+      Format(instr, "fctidu  'Dt, 'Db");
+      break;
+    }
+    case FCTIDUZ: {
+      Format(instr, "fctiduz 'Dt, 'Db");
+      break;
+    }
     case FCTIW: {
       Format(instr, "fctiw'. 'Dt, 'Db");
       break;