PPC: [turbofan] Implemented the TruncateFloat64ToUint64 TurboFan operator.

src/ppc/assembler-ppc.cc

Index: src/ppc/assembler-ppc.cc
diff --git a/src/ppc/assembler-ppc.cc b/src/ppc/assembler-ppc.cc
index 92010b6ceef2c200a2ee988e8d85267d6f7a2a2f..700db504bb687274e36d89fc300e341d0c21cfb1 100644
--- a/src/ppc/assembler-ppc.cc
+++ b/src/ppc/assembler-ppc.cc
@@ -2193,6 +2193,18 @@ void Assembler::fctidz(const DoubleRegister frt, const DoubleRegister frb,
 }
 
 
+void Assembler::fctidu(const DoubleRegister frt, const DoubleRegister frb,
+                       RCBit rc) {
+  emit(EXT4 | FCTIDU | frt.code() * B21 | frb.code() * B11 | rc);
+}
+
+
+void Assembler::fctiduz(const DoubleRegister frt, const DoubleRegister frb,
+                        RCBit rc) {
+  emit(EXT4 | FCTIDUZ | frt.code() * B21 | frb.code() * B11 | rc);
+}
+
+
 void Assembler::fsel(const DoubleRegister frt, const DoubleRegister fra,
                      const DoubleRegister frc, const DoubleRegister frb,
                      RCBit rc) {