Change char_traits<char16_t>::eof() to return 0xFFFF instead of 0xDFFF. Fixes PR#24342

llvm-svn: 243937
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 2d265aee083ed6a1ce1f51cac25ff70204aeeb77
diff --git a/include/string b/include/string
index 5777ee2..2c677ce 100644
--- a/include/string
+++ b/include/string
@@ -742,7 +742,7 @@
     static inline _LIBCPP_CONSTEXPR bool eq_int_type(int_type __c1, int_type __c2) _NOEXCEPT
         {return __c1 == __c2;}
     static inline _LIBCPP_CONSTEXPR int_type eof() _NOEXCEPT
-        {return int_type(0xDFFF);}
+        {return int_type(0xFFFF);}
 };
 
 inline _LIBCPP_INLINE_VISIBILITY