After performing scavenge, hint OS that data in from spaces are no more neede...

src/platform-macos.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 323 matching lines @@
 }
 
 
 bool VirtualMemory::Uncommit(void* address, size_t size) {
   return mmap(address, size, PROT_NONE,
               MAP_PRIVATE | MAP_ANON | MAP_NORESERVE | MAP_FIXED,
               kMmapFd, kMmapFdOffset) != MAP_FAILED;
 }
 
 
+bool VirtualMemory::Reset(void* address, size_t size, bool is_executable) {
+  return false;
+}
+
+
 class ThreadHandle::PlatformData : public Malloced {
  public:
   explicit PlatformData(ThreadHandle::Kind kind) {
     Initialize(kind);
   }
 
   void Initialize(ThreadHandle::Kind kind) {
     switch (kind) {
       case ThreadHandle::SELF: thread_ = pthread_self(); break;
       case ThreadHandle::INVALID: thread_ = kNoThread; break;
@@ skipping 285 matching lines @@
 
   // Deallocate Mach port for thread.
   if (IsProfiling()) {
     mach_port_deallocate(data_->task_self_, data_->profiled_thread_);
   }
 }
 
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
 } }  // namespace v8::internal