Introduce helper functions to test parallel recompilation.

src/runtime-profiler.cc

Index: src/runtime-profiler.cc
diff --git a/src/runtime-profiler.cc b/src/runtime-profiler.cc
index 23f41fa7d21cce30aace740db33228b6e9192acd..5b2733356d243ce28dc366cafb66f08b37c9b10f 100644
--- a/src/runtime-profiler.cc
+++ b/src/runtime-profiler.cc
@@ -140,6 +140,9 @@ static void GetICCounts(JSFunction* function,
 
 void RuntimeProfiler::Optimize(JSFunction* function, const char* reason) {
   ASSERT(function->IsOptimizable());
+  // If we are in manual mode, don't auto-optimize anything.
+  if (FLAG_manual_parallel_recompilation) return;
+
   if (FLAG_trace_opt) {
     PrintF("[marking ");
     function->PrintName();