Fix some -Wundef issues. git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@228266 91177308-0d34-0410-b5e6-96231b3b80d8 
diff --git a/include/__refstring b/include/__refstring index 6866bf1..61ccc75 100644 --- a/include/__refstring +++ b/include/__refstring 
@@ -13,7 +13,7 @@  #include <__config>  #include <cstddef>  #include <cstring> -#if __APPLE__ +#ifdef __APPLE__  #include <dlfcn.h>  #include <mach-o/dyld.h>  #endif @@ -49,7 +49,7 @@  return data + sizeof(*rep);  }   -#if __APPLE__ +#ifdef __APPLE__  static  const char*  compute_gcc_empty_string_storage() _NOEXCEPT