Fulfill some code serializer related TODOs.

src/lithium.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/lithium.h"
 
 #include "src/v8.h"
 
 #include "src/scopes.h"
 #include "src/serialize.h"
@@ skipping 445 matching lines @@
 
   return chunk;
 }
 
 
 Handle<Code> LChunk::Codegen() {
   MacroAssembler assembler(info()->isolate(), NULL, 0);
   LOG_CODE_EVENT(info()->isolate(),
                  CodeStartLinePosInfoRecordEvent(
                      assembler.positions_recorder()));
-  // TODO(yangguo) remove this once the code serializer handles code stubs.
-  if (info()->will_serialize()) assembler.enable_serializer();
+  // Code serializer only takes unoptimized code.
+  DCHECK(!info()->will_serialize());
   LCodeGen generator(this, &assembler, info());
 
   MarkEmptyBlocks();
 
   if (generator.GenerateCode()) {
     generator.CheckEnvironmentUsage();
     CodeGenerator::MakeCodePrologue(info(), "optimized");
     Code::Flags flags = info()->flags();
     Handle<Code> code =
         CodeGenerator::MakeCodeEpilogue(&assembler, flags, info());
@@ skipping 184 matching lines @@
 
 
 LPhase::~LPhase() {
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceLithium(name(), chunk_);
   }
 }
 
 
 } }  // namespace v8::internal