Inline number to string conversion for string addition into BinaryOp(Stub).

src/code-stubs.cc

Index: src/code-stubs.cc
diff --git a/src/code-stubs.cc b/src/code-stubs.cc
index 068113779910f4d5215b6599757bd412189a9dc4..09389eac7a765c3107aa20069344a9cef178d969 100644
--- a/src/code-stubs.cc
+++ b/src/code-stubs.cc
@@ -570,14 +570,8 @@ void BinaryOpStub::UpdateStatus(Handle<Object> left,
 
   State max_input = Max(left_state_, right_state_);
 
-  // TODO(olivf) Instead of doing this normalization we should have a Hydrogen
-  // version of the LookupNumberStringCache to avoid a converting StringAddStub.
-  if (left_state_ == STRING && right_state_ < STRING) {
-    right_state_ = GENERIC;
-  } else if (right_state_ == STRING && left_state_ < STRING) {
-    left_state_ = GENERIC;
-  } else if (!has_int_result() && op_ != Token::SHR &&
-             max_input <= NUMBER && max_input > result_state_) {
+  if (!has_int_result() && op_ != Token::SHR &&
+      max_input <= NUMBER && max_input > result_state_) {
     result_state_ = max_input;
   }
 
@@ -1127,6 +1121,12 @@ void ArrayConstructorStubBase::InstallDescriptors(Isolate* isolate) {
 }
 
 
+void NumberToStringStub::InstallDescriptors(Isolate* isolate) {
+  NumberToStringStub stub;
+  InstallDescriptor(isolate, &stub);
+}
+
+
 void FastNewClosureStub::InstallDescriptors(Isolate* isolate) {
   FastNewClosureStub stub(STRICT_MODE, false);
   InstallDescriptor(isolate, &stub);