[turbofan] Enable concurrent (re)compilation.

src/optimizing-compile-dispatcher.cc

Index: src/optimizing-compile-dispatcher.cc
diff --git a/src/optimizing-compile-dispatcher.cc b/src/optimizing-compile-dispatcher.cc
index f5c57cd1cfbb81bc36492d88dca4bf96bb1b12c0..b28e870e1cd03eb637606aa24da452751b8461ed 100644
--- a/src/optimizing-compile-dispatcher.cc
+++ b/src/optimizing-compile-dispatcher.cc
@@ -33,6 +33,8 @@ void DisposeOptimizedCompileJob(OptimizedCompileJob* job,
       function->ReplaceCode(function->shared()->code());
     }
   }
+  // TODO(bmeurer): Improve resource management for OptimizedCompileJob.
+  job->~OptimizedCompileJob();
   delete info;
 }