CTZ instruction implemented as optional operator.

src/compiler/typer.cc

Index: src/compiler/typer.cc
diff --git a/src/compiler/typer.cc b/src/compiler/typer.cc
index 4707aef1e519cafcb5de1d29375ca4f5be8e9e77..0265c28ea9af2e1c4925dea741b0de7e1f5b5af7 100644
--- a/src/compiler/typer.cc
+++ b/src/compiler/typer.cc
@@ -1698,6 +1698,9 @@ Type* Typer::Visitor::TypeWord32Equal(Node* node) { return Type::Boolean(); }
 Type* Typer::Visitor::TypeWord32Clz(Node* node) { return Type::Integral32(); }
 
 
+Type* Typer::Visitor::TypeWord32Ctz(Node* node) { return Type::Integral32(); }
+
+
 Type* Typer::Visitor::TypeWord64And(Node* node) { return Type::Internal(); }