[turbofan] Added the RoundInt64ToFloat64 instruction to TurboFan.

src/compiler/raw-machine-assembler.h

Index: src/compiler/raw-machine-assembler.h
diff --git a/src/compiler/raw-machine-assembler.h b/src/compiler/raw-machine-assembler.h
index cfb88ef7b39a73c7685af62dfd78d854e2925fee..4dd199ca7ad3ead7fba21d14fc46048f45a89b8d 100644
--- a/src/compiler/raw-machine-assembler.h
+++ b/src/compiler/raw-machine-assembler.h
@@ -433,6 +433,9 @@ class RawMachineAssembler {
   Node* ChangeInt32ToFloat64(Node* a) {
     return AddNode(machine()->ChangeInt32ToFloat64(), a);
   }
+  Node* ChangeInt64ToFloat64(Node* a) {
+    return AddNode(machine()->ChangeInt64ToFloat64(), a);
+  }
   Node* ChangeUint32ToFloat64(Node* a) {
     return AddNode(machine()->ChangeUint32ToFloat64(), a);
   }