CTZ instruction implemented as optional operator.

src/ia32/macro-assembler-ia32.h

Index: src/ia32/macro-assembler-ia32.h
diff --git a/src/ia32/macro-assembler-ia32.h b/src/ia32/macro-assembler-ia32.h
index d52249437324fe28300f9cfe410cebff7508d35c..37d1282a2567661e4ebbc179f635d57b0be38165 100644
--- a/src/ia32/macro-assembler-ia32.h
+++ b/src/ia32/macro-assembler-ia32.h
@@ -854,6 +854,9 @@ class MacroAssembler: public Assembler {
   void Lzcnt(Register dst, Register src) { Lzcnt(dst, Operand(src)); }
   void Lzcnt(Register dst, const Operand& src);
 
+  void Tzcnt(Register dst, Register src) { Tzcnt(dst, Operand(src)); }
+  void Tzcnt(Register dst, const Operand& src);
+
   // Emit call to the code we are currently generating.
   void CallSelf() {
     Handle<Code> self(reinterpret_cast<Code**>(CodeObject().location()));