Improve trace_opt output to help find compilation problems

src/heap.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 3273 matching lines @@
 
 MaybeObject* Heap::AllocateSharedFunctionInfo(Object* name) {
   SharedFunctionInfo* share;
   MaybeObject* maybe = Allocate(shared_function_info_map(), OLD_POINTER_SPACE);
   if (!maybe->To<SharedFunctionInfo>(&share)) return maybe;
 
   // Set pointer fields.
   share->set_name(name);
   Code* illegal = isolate_->builtins()->builtin(Builtins::kIllegal);
   share->set_code(illegal);
-  share->ClearOptimizedCodeMap();
+  share->set_optimized_code_map(Smi::FromInt(0));
   share->set_scope_info(ScopeInfo::Empty(isolate_));
   Code* construct_stub =
       isolate_->builtins()->builtin(Builtins::kJSConstructStubGeneric);
   share->set_construct_stub(construct_stub);
   share->set_instance_class_name(Object_string());
   share->set_function_data(undefined_value(), SKIP_WRITE_BARRIER);
   share->set_script(undefined_value(), SKIP_WRITE_BARRIER);
   share->set_debug_info(undefined_value(), SKIP_WRITE_BARRIER);
   share->set_inferred_name(empty_string(), SKIP_WRITE_BARRIER);
   share->set_initial_map(undefined_value(), SKIP_WRITE_BARRIER);
@@ skipping 4578 matching lines @@
   if (FLAG_parallel_recompilation) {
     heap_->relocation_mutex_->Lock();
 #ifdef DEBUG
     heap_->relocation_mutex_locked_by_optimizer_thread_ =
         heap_->isolate()->optimizing_compiler_thread()->IsOptimizerThread();
 #endif  // DEBUG
   }
 }
 
 } }  // namespace v8::internal