PPC64: Implemented the Word64Clz 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 9b04ec9e5f362afce3374240ca5912f09dbd53a6..73fb41c87ba3dacccbe616dd662c47bb14bbd42c 100644
--- a/src/compiler/ppc/instruction-selector-ppc.cc
+++ b/src/compiler/ppc/instruction-selector-ppc.cc
@@ -737,6 +737,14 @@ void InstructionSelector::VisitWord32Clz(Node* node) {
 }
 
 
+#if V8_TARGET_ARCH_PPC64
+void InstructionSelector::VisitWord64Clz(Node* node) {
+  PPCOperandGenerator g(this);
+  Emit(kPPC_Cntlz64, g.DefineAsRegister(node), g.UseRegister(node->InputAt(0)));
+}
+#endif
+
+
 void InstructionSelector::VisitWord32Popcnt(Node* node) {
   PPCOperandGenerator g(this);
   Emit(kPPC_Popcnt32, g.DefineAsRegister(node),