[turbofan] Implemented the TruncateFloat64ToUint64 TurboFan operator.

src/compiler/ppc/instruction-selector-ppc.cc

Index: src/compiler/ppc/instruction-selector-ppc.cc
diff --git a/src/compiler/ppc/instruction-selector-ppc.cc b/src/compiler/ppc/instruction-selector-ppc.cc
index e825e3af7ceefeafedadce0fb75dedede2fadd53..832a360402cbdc9613f9f2bbc7b31d77511716d6 100644
--- a/src/compiler/ppc/instruction-selector-ppc.cc
+++ b/src/compiler/ppc/instruction-selector-ppc.cc
@@ -932,6 +932,11 @@ void InstructionSelector::VisitChangeFloat64ToInt64(Node* node) {
 }
 
 
+void InstructionSelector::VisitTruncateFloat64ToUint64(Node* node) {
+  UNIMPLEMENTED();
+}
+
+
 void InstructionSelector::VisitChangeInt32ToInt64(Node* node) {
   // TODO(mbrandy): inspect input to see if nop is appropriate.
   VisitRR(this, kPPC_ExtendSignWord32, node);