[debugger] Re-enable --always-opt in one debugger test.

test/cctest/test-debug.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 6688 matching lines @@
 
 
 // Test that debug messages get processed when ProcessDebugMessages is called.
 TEST(Backtrace) {
   DebugLocalContext env;
   v8::Isolate* isolate = env->GetIsolate();
   v8::HandleScope scope(isolate);
 
   v8::Debug::SetMessageHandler(BacktraceData::MessageHandler);
 
-  // TODO(mstarzinger): This doesn't work with --always-opt because we don't
-  // have correct source positions in optimized code. Enable once we have.
-  i::FLAG_always_opt = false;
-
   const int kBufferSize = 1000;
   uint16_t buffer[kBufferSize];
   const char* scripts_command =
     "{\"seq\":0,"
      "\"type\":\"request\","
      "\"command\":\"backtrace\"}";
 
   // Check backtrace from ProcessDebugMessages.
   BacktraceData::frame_counter = -10;
   v8::Debug::SendCommand(
@@ skipping 927 matching lines @@
   CompileRun("function foo() {}; foo();");
   --after_compile_handler_depth;
 }
 
 
 TEST(NoInterruptsInDebugListener) {
   DebugLocalContext env;
   v8::Debug::SetDebugEventListener(NoInterruptsOnDebugEvent);
   CompileRun("void(0);");
 }