Implement handlified String::Flatten.

src/hydrogen.cc

 // Copyright 2013 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 4911 matching lines @@
       }
 
       if (type == kUseCell) {
         Handle<GlobalObject> global(current_info()->global_object());
         Handle<PropertyCell> cell(global->GetPropertyCell(&lookup));
         if (cell->type()->IsConstant()) {
           cell->AddDependentCompilationInfo(top_info());
           Handle<Object> constant_object = cell->type()->AsConstant();
           if (constant_object->IsConsString()) {
             constant_object =
-                FlattenGetString(Handle<String>::cast(constant_object));
+                String::Flatten(Handle<String>::cast(constant_object));
           }
           HConstant* constant = New<HConstant>(constant_object);
           return ast_context()->ReturnInstruction(constant, expr->id());
         } else {
           HLoadGlobalCell* instr =
               New<HLoadGlobalCell>(cell, lookup.GetPropertyDetails());
           return ast_context()->ReturnInstruction(instr, expr->id());
         }
       } else {
         HValue* global_object = Add<HLoadNamedField>(
@@ skipping 6559 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal