Handle string + number in hydrogen.

src/code-stubs.cc

Index: src/code-stubs.cc
diff --git a/src/code-stubs.cc b/src/code-stubs.cc
index 2283f847bab674029ae9e6d1f881e431589a60fc..6ea154bb0fbb264cc975f1785a7d51f98eeb10de 100644
--- a/src/code-stubs.cc
+++ b/src/code-stubs.cc
@@ -569,14 +569,8 @@ 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;
   }