PPC64: Implemented the RoundUint64ToFloat64 TurboFan operator.

src/ppc/macro-assembler-ppc.cc

Index: src/ppc/macro-assembler-ppc.cc
diff --git a/src/ppc/macro-assembler-ppc.cc b/src/ppc/macro-assembler-ppc.cc
index e543ba853bc00767d8c19d0cae27ed9aa5566294..711422af926eda870e6f8aded7f9f2856473099e 100644
--- a/src/ppc/macro-assembler-ppc.cc
+++ b/src/ppc/macro-assembler-ppc.cc
@@ -671,6 +671,13 @@ void MacroAssembler::ConvertInt64ToDouble(Register src,
 }
 
 
+void MacroAssembler::ConvertUnsignedInt64ToDouble(Register src,
+                                                  DoubleRegister double_dst) {
+  MovInt64ToDouble(double_dst, src);
+  fcfidu(double_dst, double_dst);
+}
+
+
 void MacroAssembler::ConvertInt64ToFloat(Register src,
                                          DoubleRegister double_dst) {
   MovInt64ToDouble(double_dst, src);