Fix leakage of virtual address space on Linux platform.

src/platform-openbsd.cc

 // Copyright 2006-2011 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 227 matching lines @@
     fclose(file);
     return NULL;
   }
   void* memory =
       mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fileno(file), 0);
   return new PosixMemoryMappedFile(file, memory, size);
 }
 
 
 PosixMemoryMappedFile::~PosixMemoryMappedFile() {
-  if (memory_) munmap(memory_, size_);
+  if (memory_) OS::Free(memory_, size_);
   fclose(file_);
 }
 
 
 static unsigned StringToLong(char* buffer) {
   return static_cast<unsigned>(strtol(buffer, NULL, 16));  // NOLINT
 }
 
 
 void OS::LogSharedLibraryAddresses() {
@@ skipping 76 matching lines @@
 VirtualMemory::VirtualMemory(size_t size) {
   address_ = mmap(NULL, size, PROT_NONE,
                   MAP_PRIVATE | MAP_ANON | MAP_NORESERVE,
                   kMmapFd, kMmapFdOffset);
   size_ = size;
 }
 
 
 VirtualMemory::~VirtualMemory() {
   if (IsReserved()) {
-    if (0 == munmap(address(), size())) address_ = MAP_FAILED;
+    OS::Free(address(), size());
+    address_ = MAP_FAILED
   }
 }
 
 
 bool VirtualMemory::IsReserved() {
   return address_ != MAP_FAILED;
 }
 
 
 bool VirtualMemory::Commit(void* address, size_t size, bool executable) {
@@ skipping 437 matching lines @@
 
 
 void Sampler::Stop() {
   ASSERT(IsActive());
   SignalSender::RemoveActiveSampler(this);
   SetActive(false);
 }
 
 
 } }  // namespace v8::internal