ARM64: Fix native builds

On ARM64, HasListItem() isn't used, so the compiler complains. Use the
preprocessor to remove it from ARM64 builds.

BUG=
R=ulan@chromium.org

Review URL: https://codereview.chromium.org/285463003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21285 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/cpu.cc

@@ -206,6 +206,7 @@ class CPUInfo V8_FINAL BASE_EMBEDDED {
   size_t datalen_;
 };
 
+#if V8_HOST_ARCH_ARM || V8_HOST_ARCH_MIPS
 
 // Checks that a space-separated list of items contains one given 'item'.
 static bool HasListItem(const char* list, const char* item) {
@@ -231,6 +232,8 @@ static bool HasListItem(const char* list, const char* item) {
   return false;
 }
 
+#endif  // V8_HOST_ARCH_ARM || V8_HOST_ARCH_MIPS
+
 #endif  // V8_OS_LINUX
 
 #endif  // V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64