[turbofan] Added the RoundInt64ToFloat64 instruction to TurboFan.

src/compiler/arm64/instruction-selector-arm64.cc

Index: src/compiler/arm64/instruction-selector-arm64.cc
diff --git a/src/compiler/arm64/instruction-selector-arm64.cc b/src/compiler/arm64/instruction-selector-arm64.cc
index bf7d54dfe3a71ac250ab39e6b72dca0f6fd289f5..f2958868fb8f4838c6f92dfd2302f54bdea62ae6 100644
--- a/src/compiler/arm64/instruction-selector-arm64.cc
+++ b/src/compiler/arm64/instruction-selector-arm64.cc
@@ -1188,6 +1188,11 @@ void InstructionSelector::VisitChangeInt32ToFloat64(Node* node) {
 }
 
 
+void InstructionSelector::VisitChangeInt64ToFloat64(Node* node) {
+  VisitRR(this, kArm64Int64ToFloat64, node);
+}
+
+
 void InstructionSelector::VisitChangeUint32ToFloat64(Node* node) {
   VisitRR(this, kArm64Uint32ToFloat64, node);
 }