[turbofan] Unify BooleanToNumber, StringToNumber and PlainPrimitiveToNumber.

src/compiler/typer.cc

Index: src/compiler/typer.cc
diff --git a/src/compiler/typer.cc b/src/compiler/typer.cc
index ce8a5636233c1476de497b1db9e3c2615ce48337..c00eff454a9a2f2054a605c8d03362325e9b2dc4 100644
--- a/src/compiler/typer.cc
+++ b/src/compiler/typer.cc
@@ -1557,10 +1557,6 @@ Type* Typer::Visitor::TypeJSStackCheck(Node* node) { return Type::Any(); }
 
 Type* Typer::Visitor::TypeBooleanNot(Node* node) { return Type::Boolean(); }
 
-Type* Typer::Visitor::TypeBooleanToNumber(Node* node) {
-  return TypeUnaryOp(node, ToNumber);
-}
-
 Type* Typer::Visitor::TypeNumberEqual(Node* node) { return Type::Boolean(); }
 
 Type* Typer::Visitor::TypeNumberLessThan(Node* node) { return Type::Boolean(); }
@@ -1779,10 +1775,6 @@ Type* Typer::Visitor::TypeStringFromCharCode(Node* node) {
   return TypeUnaryOp(node, StringFromCharCodeTyper);
 }
 
-Type* Typer::Visitor::TypeStringToNumber(Node* node) {
-  return TypeUnaryOp(node, ToNumber);
-}
-
 Type* Typer::Visitor::TypeCheckBounds(Node* node) {
   // TODO(bmeurer): We could do better here based on the limit.
   return Type::Unsigned31();