Get rid of HStringLength.

src/hydrogen.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1219 matching lines @@
       HValue* object,
       HValue* key,
       HValue* val,
       HCheckMaps* mapcheck,
       bool is_js_array,
       ElementsKind elements_kind,
       bool is_store,
       LoadKeyedHoleMode load_mode,
       KeyedAccessStoreMode store_mode);
 
-  HLoadNamedField* BuildLoadNamedField(
-      HValue* object,
-      HObjectAccess access);
-
   HInstruction* AddExternalArrayElementAccess(
       HValue* external_elements,
       HValue* checked_key,
       HValue* val,
       HValue* dependency,
       ElementsKind elements_kind,
       bool is_store);
 
   HInstruction* AddFastElementAccess(
       HValue* elements,
       HValue* checked_key,
       HValue* val,
       HValue* dependency,
       ElementsKind elements_kind,
       bool is_store,
       LoadKeyedHoleMode load_mode,
       KeyedAccessStoreMode store_mode);
 
+  HLoadNamedField* BuildLoadNamedField(
+      HValue* object,
+      HObjectAccess access,
+      HValue* typecheck = NULL);
+  HInstruction* BuildLoadStringLength(HValue* object, HValue* typecheck = NULL);
   HStoreNamedField* AddStoreMapConstant(HValue *object, Handle<Map>);
   HLoadNamedField* AddLoadElements(HValue *object, HValue *typecheck = NULL);
   HLoadNamedField* AddLoadFixedArrayLength(HValue *object);
 
   HValue* AddLoadJSBuiltin(Builtins::JavaScript builtin);
 
   HValue* TruncateToNumber(HValue* value, Handle<Type>* expected);
 
   void PushAndAdd(HInstruction* instr);
 
@@ skipping 1053 matching lines @@
   EmbeddedVector<char, 64> filename_;
   HeapStringAllocator string_allocator_;
   StringStream trace_;
   int indent_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_H_