Don't check symbol literals for being symbols.

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index cc32b93831ebe2efebdb2b6cb6d6d3b39cb3b65a..86d97da43901d63e3bcab4671cb4ba9ef191255b 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -2003,14 +2003,7 @@ class HCheckInstanceType: public HUnaryOperation {
   virtual void Verify();
 #endif
 
-  virtual HValue* Canonicalize() {
-    if (!value()->type().IsUninitialized() &&
-        value()->type().IsString() &&
-        check_ == IS_STRING) {
-      return NULL;
-    }
-    return this;
-  }
+  virtual HValue* Canonicalize();
 
   bool is_interval_check() const { return check_ <= LAST_INTERVAL_CHECK; }
   void GetCheckInterval(InstanceType* first, InstanceType* last);