Drop unused v8threads include from platform files

src/platform-linux.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Platform-specific code for Linux goes here. For the POSIX-compatible
 // parts, the implementation is in platform-posix.cc.
 
 #include <pthread.h>
 #include <semaphore.h>
 #include <signal.h>
@@ skipping 26 matching lines @@
 
 #if defined(LEAK_SANITIZER)
 #include <sanitizer/lsan_interface.h>
 #endif
 
 #undef MAP_TYPE
 
 #include "src/v8.h"
 
 #include "src/platform.h"
-#include "src/v8threads.h"
 
 
 namespace v8 {
 namespace internal {
 
 
 #ifdef __arm__
 
 bool OS::ArmUsingHardFloat() {
   // GCC versions 4.6 and above define __ARM_PCS or __ARM_PCS_VFP to specify
@@ skipping 367 matching lines @@
 #endif
   return munmap(base, size) == 0;
 }
 
 
 bool VirtualMemory::HasLazyCommits() {
   return true;
 }
 
 } }  // namespace v8::internal