Support profiling based on linux kernel performance events.

src/platform-nullos.cc

 // Copyright 2006-2008 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 222 matching lines @@
   UNIMPLEMENTED();
   return NULL;
 }
 
 
 void OS::LogSharedLibraryAddresses() {
   UNIMPLEMENTED();
 }
 
 
+void OS::SignalCodeMovingGC() {
+  UNIMPLEMENTED();
+}
+
+
 int OS::StackWalk(Vector<OS::StackFrame> frames) {
   UNIMPLEMENTED();
   return 0;
 }
 
 
 VirtualMemory::VirtualMemory(size_t size, void* address_hint) {
   UNIMPLEMENTED();
 }
 
@@ skipping 198 matching lines @@
 }
 
 
 void ProfileSampler::Stop() {
   UNIMPLEMENTED();
 }
 
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
 } }  // namespace v8::internal