[turbofan] Enable concurrent (re)compilation.

src/compiler.h

 // 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.
 
 #ifndef V8_COMPILER_H_
 #define V8_COMPILER_H_
 
 #include "src/allocation.h"
 #include "src/ast/ast.h"
 #include "src/bailout-reason.h"
@@ skipping 553 matching lines @@
 // A base class for compilation jobs intended to run concurrent to the main
 // thread. The job is split into three phases which are called in sequence on
 // different threads and with different limitations:
 //  1) CreateGraph:   Runs on main thread. No major limitations.
 //  2) OptimizeGraph: Runs concurrently. No heap allocation or handle derefs.
 //  3) GenerateCode:  Runs on main thread. No dependency changes.
 //
 // Each of the three phases can either fail, bail-out to full code generator or
 // succeed. Apart from their return value, the status of the phase last run can
 // be checked using {last_status()} as well.
-class OptimizedCompileJob: public ZoneObject {
+// TODO(mstarzinger): Make CompilationInfo base embedded.
+class OptimizedCompileJob {
  public:
   explicit OptimizedCompileJob(CompilationInfo* info, const char* compiler_name)
       : info_(info), compiler_name_(compiler_name), last_status_(SUCCEEDED) {}
   virtual ~OptimizedCompileJob() {}
 
   enum Status {
     FAILED, BAILED_OUT, SUCCEEDED
   };
 
   MUST_USE_RESULT Status CreateGraph();
@@ skipping 35 matching lines @@
   MUST_USE_RESULT Status SetLastStatus(Status status) {
     last_status_ = status;
     return last_status_;
   }
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_H_