Check that environments assigned via AssignEnvironment are actually used.

src/lithium.cc

 // 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 414 matching lines @@
 Handle<Code> LChunk::Codegen() {
   MacroAssembler assembler(info()->isolate(), NULL, 0);
   LOG_CODE_EVENT(info()->isolate(),
                  CodeStartLinePosInfoRecordEvent(
                      assembler.positions_recorder()));
   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());
     generator.FinishCode(code);
     code->set_is_crankshafted(true);
     void* jit_handler_data =
         assembler.positions_recorder()->DetachJITHandlerData();
     LOG_CODE_EVENT(info()->isolate(),
                    CodeEndLinePosInfoRecordEvent(*code, jit_handler_data));
@@ skipping 164 matching lines @@
 
 
 LPhase::~LPhase() {
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceLithium(name(), chunk_);
   }
 }
 
 
 } }  // namespace v8::internal