Add --trace-hydrogen-stubs flag (default = false).

src/code-stubs-hydrogen.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 111 matching lines @@
   CompilationInfoWithZone info_;
   CodeStubInterfaceDescriptor* descriptor_;
   HContext* context_;
 };
 
 
 bool CodeStubGraphBuilderBase::BuildGraph() {
   // Update the static counter each time a new code stub is generated.
   isolate()->counters()->code_stubs()->Increment();
 
-  if (FLAG_trace_hydrogen) {
+  if (FLAG_trace_hydrogen_stubs) {
     const char* name = CodeStub::MajorName(stub()->MajorKey(), false);
     PrintF("-----------------------------------------------------------\n");
     PrintF("Compiling stub %s using hydrogen\n", name);
     isolate()->GetHTracer()->TraceCompilation(&info_);
   }
 
   Zone* zone = this->zone();
   int param_count = descriptor_->register_param_count_;
   HEnvironment* start_environment = graph()->start_environment();
   HBasicBlock* next_block = CreateBasicBlock(start_environment);
@@ skipping 809 matching lines @@
   return value;
 }
 
 
 Handle<Code> ElementsTransitionAndStoreStub::GenerateCode() {
   return DoGenerateCode(this);
 }
 
 
 } }  // namespace v8::internal