Use std:: on symbols declared in C++-style C headers.

src/cpu.cc

 // Copyright 2013 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 19 matching lines @@
 #if V8_CC_MSVC
 #include <intrin.h>  // __cpuid()
 #endif
 #if V8_OS_POSIX
 #include <unistd.h>  // sysconf()
 #endif
 #if V8_OS_QNX
 #include <sys/syspage.h>  // cpuinfo
 #endif
 
+#include <ctype.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 #include <algorithm>
-#include <cctype>
-#include <climits>
-#include <cstdio>
-#include <cstdlib>
-#include <cstring>
 
 #include "checks.h"
 #if V8_OS_WIN
 #include "win32-headers.h"
 #endif
 
 namespace v8 {
 namespace internal {
 
 #if V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64
@@ skipping 440 matching lines @@
 #if V8_OS_WIN
   SYSTEM_INFO info;
   GetSystemInfo(&info);
   return info.dwNumberOfProcessors;
 #else
   return static_cast<int>(sysconf(_SC_NPROCESSORS_ONLN));
 #endif
 }
 
 } }  // namespace v8::internal