[turbofan] Implemented the TruncateFloat64ToUint64 TurboFan operator.

src/compiler/x64/instruction-selector-x64.cc

Index: src/compiler/x64/instruction-selector-x64.cc
diff --git a/src/compiler/x64/instruction-selector-x64.cc b/src/compiler/x64/instruction-selector-x64.cc
index 0563e432905f33446b67596213da14762bad1c81..11ce7c436233969f437c1b5d822e46fd61b60651 100644
--- a/src/compiler/x64/instruction-selector-x64.cc
+++ b/src/compiler/x64/instruction-selector-x64.cc
@@ -840,6 +840,12 @@ void InstructionSelector::VisitChangeFloat64ToInt64(Node* node) {
 }
 
 
+void InstructionSelector::VisitTruncateFloat64ToUint64(Node* node) {
+  X64OperandGenerator g(this);
+  Emit(kSSEFloat64ToUint64, g.DefineAsRegister(node), g.Use(node->InputAt(0)));
+}
+
+
 void InstructionSelector::VisitChangeInt32ToInt64(Node* node) {
   X64OperandGenerator g(this);
   Emit(kX64Movsxlq, g.DefineAsRegister(node), g.Use(node->InputAt(0)));